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Department of Animal Sciences
The Robert H. Smith Faculty
of Agricultural, Food & Environment

The Hebrew University of Jerusalem.

P.O. Box 12, Rehovot 76100, Israel
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2020
Roth, Z. ; Dvir, A. ; Furman, O. ; Lavon, Y. ; Kalo, D. ; Leitner, G. ; Wolfenson, D. Oocyte maturation in plasma or follicular fluid obtained from lipopolysaccharide-treated cows disrupts its developmental competence. Theriogenology 2020, 141, 120-127. Publisher's VersionAbstract
Mastitis has deleterious effects on ovarian function and reproductive performance. We studied the association between plasma or follicular fluid (FF) obtained from endotoxin-induced mastitic cows, and oocyte developmental competence. Lactating Holstein cows were synchronized using the Ovsynch protocol. On Day 6 of the synchronized cycle, an additional PGF2α dose was administered, and either Escherichia coli endotoxin (LPS, 10 μg; n = 3 cows) or saline (n = 3 cows) was administered to one udder quarter per cow, 36 h later. Milk samples were collected and rectal temperatures recorded. Cows treated with LPS showed a typical transient increase in body temperature (40.3 °C ± 0.4), whereas cows treated with saline maintained normal body temperature (38.9 °C ± 0.04). A higher (P < 0.05) somatic cell count was recorded for cows treated with LPS. Plasma samples were collected and FF was aspirated from the preovulatory follicles by transvaginal ultrasound probe, 6 h after LPS administration. Radioimmunoassay was performed on plasma samples to determine estradiol and cortisol concentrations. Either FF or plasma was further used as maturation medium. In the first experiment, oocytes were matured in TCM-199 (Control) or in FF aspirated from cows treated with saline (FF-Saline) or LPS (FF-LPS). Cleavage rate to the 2- to 4-cell stage embryo did not differ among groups. However, the proportion of developed blastocysts on Day 7 postfertilization in the FF-LPS group tended to be lower for that in FF-Saline and was lower (P < 0.05) than that in the Control groups (10.6 vs. 22.4 and 24.4%, respectively). In the second experiment, oocytes were matured in TCM-199 (Control), or in plasma obtained from cows treated with saline (Plasma-Saline) or LPS (Plasma-LPS). Similar to the FF findings, cleavage rate did not differ among groups; however, the proportion of developing blastocysts tended to be lower in the Plasma-LPS group than in the Plasma-Saline group and was lower (P < 0.05) from that in the Control group (11.0 vs. 25.5 and 34.7%, respectively). The proportion of apoptotic cells per blastocyst, determined by TUNEL assay, did not differ among the experimental groups. The findings shed light on the mechanism by which mastitis induces a disruption in oocyte developmental competence. Further studies are required to clarify whether the negative effect on oocyte developmental competence is a result of LPS, by itself, or due to elevation of secondary inflammatory agents. © 2019
Burow, S. ; Mizrahi, N. ; Maugars, G. ; von Krogh, K. ; Nourizadeh-Lillabadi, R. ; Hollander-Cohen, L. ; Shpilman, M. ; Atre, I. ; Weltzien, F. - A. ; Levavi-Sivan, B. Characterization of gonadotropin receptors Fshr and Lhr in Japanese medaka, Oryzias latipes. General and Comparative Endocrinology 2020, 285. Publisher's VersionAbstract
Reproduction in vertebrates is controlled by the brain-pituitary-gonad axis, where the two gonadotropins follicle-stimulating hormone (Fsh) and luteinizing hormone (Lh) play vital parts by activating their cognate receptors in the gonads. The main purpose of this work was to study intra- and interspecies ligand promiscuity of teleost gonadotropin receptors, since teleost receptor specificity is unclear, in contrast to mammalian receptors. Receptor activation was investigated by transfecting COS-7 cells with either Fsh receptor (mdFshr, tiFshr) or Lh receptor (mdLhr, tiLhr), and tested for activation by recombinant homologous and heterologous ligands (mdFshβα, mdLhβα, tiFshβα, tiLhβα) from two representative fish orders, Japanese medaka (Oryzias latipes, Beloniformes) and Nile tilapia (Oreochromis niloticus, Cichliformes). Results showed that each gonadotropin preferentially activates its own cognate receptor. Cross-reactivity was detected to some extent as mdFshβα was able to activate the mdLhr, and mdLhβα the mdFshr. Medaka pituitary extract (MPE) stimulated CRE-LUC activity in COS-7 cells expressing mdlhr, but could not stimulate cells expressing mdfshr. Recombinant tiLhβα, tiFshβα and tilapia pituitary extract (TPE) could activate the mdLhr, suggesting cross-species reactivity for mdLhr. Cross-species reactivity was also detected for mdFshr due to activation by tiFshβα, tiLhβα, and TPE, as well as for tiFshr and tiLhr due to stimulation by mdFshβα, mdLhβα, and MPE. Tissue distribution analysis of gene expression revealed that medaka receptors, fshr and lhr, are highly expressed in both ovary and testis. High expression levels were found for lhr also in brain, while fshr was expressed at low levels. Both fshr and lhr mRNA levels increased significantly during testis development. Amino acid sequence alignment and three-dimensional modelling of ligands and receptors highlighted conserved beta sheet domains of both Fsh and Lh between Japanese medaka and Nile tilapia. It also showed a higher structural homology and similarity of transmembrane regions of Lhr between both species, in contrast to Fshr, possibly related to the substitution of the conserved cysteine residue in the transmembrane domain 6 in medaka Fshr with glycine. Taken together, this is the first characterization of medaka Fshr and Lhr using homologous ligands, enabling to better understand teleost hormone-receptor interactions and specificities. The data suggest partial ligand promiscuity and cross-species reactivity between gonadotropins and their receptors in medaka and tilapia. © 2019 The Authors
2019
Davidson, I. ; Altory-Natour, A. ; Haddas, R. ; Nagar, S. ; Meir, R. ; Avital-Cohen, N. ; Rozenboim, I. Evaluation of viral-induced stress by quantitating corticosterone in feathers of virus-infected specific pathogen-free chicks. The Journal of Applied Poultry Research 2019. Publisher's VersionAbstract
Physiological stress is known to promote economic losses by causing immunosuppression. Various factors induce stress, including non-optimal management and infection with various pathogens. The concentration of the stress hormone, corticosterone, is indicative of stress in birds. However, its measurement is difficult due to its elevation caused by catching, handling, bleeding, short half-life in the blood, and short secretion period in feces. We describe a novel method to assess corticosterone concentration by sampling feathers. The viruses studied were 2 immunosuppressive viruses, Marek's disease virus and chicken anemia virus, the respiratory viruses, influenza virus H9N2, Newcastle disease virus, and Infectious bronchitis virus. The study contributes novelty as virus-induced stress by feather examination was described sporadically in chickens previously, and feathers were used to detect corticosterone mainly in dead wild and captive birds. Also, the development of extraction method from feathers is novel by using PBS instead of methanol, and by preparing the feather homogenate with steroid displacement reagent.The study findings revealed that virus infections increased the corticosterone concentrations in feather tips to various extents, from 2× to 10× fold, demonstrating that birds endure stress in addition to the clinical and pathological effects induced by the virus infections.
Berman, A. An overview of heat stress relief with global warming in perspective. International Journal of Biometeorology 2019, 63, 493-498. Publisher's VersionAbstract
Global warming seems more probable, whether as gradual warming or increased frequency of warmer episodes. The productivity of cattle in temperate countries will decline unless counteracting steps are adopted. The probability of pre-emptive breeding for maintaining temperate breed performance coupled with heat stress tolerance is too low to be adopted for counteracting warming. The expected warming will mostly involve temperature increases. These will indirectly affect radiant heat gain in animals owing to reduced radiant heat dissipation from the body by convective heat loss, which results in an increased sensitivity to incoming radiant heat at higher air temperatures. These necessitate an emphasis on increasing convective heat loss by structure design and forced air flow by fans. Convective heat loss diminishes with increasing air temperatures. Evaporative heat loss remains the alternative. Evaporative cooling of the ambient requires partial enclosing of the space surrounding the animals and is limited by the humidity in ambient air. An alternative was developed of coupling forced ventilation with wetting of animal surface. The exchange of ambient air flowing on animal surface makes the evaporation practically independent of air humidity and the loss of heat from animal surface practically independent of the surface to air temperature gradient. The coupling of forced ventilation with wetting combination may be attained in various parts of the dairy farm, the holding area of the milking parlour, the feeding trip and the resting area. Each of these requires differing structural and technological adaptations. Climate and farming systems vary between locations which require specific solutions. © 2019, ISB.
Eidelman, A. ; Cohen, C. ; Navarro-Castilla, Á. ; Filler, S. ; Gutiérrez, R. ; Bar-Shira, E. ; Shahar, N. ; Garrido, M. ; Halle, S. ; Romach, Y. ; et al. The dynamics between limited-term and lifelong coinfecting bacterial parasites in wild rodent hosts. Journal of Experimental Biology 2019, 222. Publisher's VersionAbstract
Interactions between coinfecting parasites may take various forms, either direct or indirect, facilitative or competitive, and may be mediated by either bottom-up or top-down mechanisms. Although each form of interaction leads to different evolutionary and ecological outcomes, it is challenging to tease them apart throughout the infection period. To establish the first step towards a mechanistic understanding of the interactions between coinfecting limited-term bacterial parasites and lifelong bacterial parasites, we studied the coinfection of Bartonella sp. (limited-term) and Mycoplasma sp. (lifelong), which commonly co-occur in wild rodents. We infected Bartonella- and Mycoplasma-free rodents with each species, and simultaneously with both, and quantified the infection dynamics and host responses. Bartonella benefited from the interaction; its infection load decreased more slowly in coinfected rodents than in rodents infected with Bartonella alone. There were no indications for bottom-up effects, but coinfected rodents experienced various changes, depending on the infection stage, in their body mass, stress levels and activity pattern, which may further affect bacterial replication and transmission. Interestingly, the infection dynamics and changes in the average coinfected rodent traits were more similar to the chronic effects of Mycoplasma infection, whereas coinfection uniquely impaired the host’s physiological and behavioral stability. These results suggest that parasites with distinct life history strategies may interact, and their interaction may be asymmetric, non-additive, multifaceted and dynamic through time. Because multiple, sometimes contrasting, forms of interactions are simultaneously at play and their relative importance alternates throughout the course of infection, the overall outcome may change under different ecological conditions. © 2019. Published by The Company of Biologists Ltd.
Azaria, S. ; Post, A. F. ; van Rijn, J. Changes in the Bacterial Community Structure of Denitrifying Sludge from a Recirculating Aquaculture System (RAS) After Geosmin and 2-Methylisoborneol Enrichment. Current Microbiology 2019. Publisher's VersionAbstract
The secondary metabolites geosmin and 2-methylisoborneol (MIB) are known to taint fish with an undesirable, earthy-muddy taste and odor. In an earlier study on a zero-discharge recirculating aquaculture system (RAS), it was found that geosmin and MIB were removed by microbial communities residing in sludge from the digestion basin of the system. In the present study, 16S amplicon sequencing was used to identify changes in relative abundances of bacterial taxa in geosmin and MIB-enriched crude sludge. The removal of geosmin and MIB by the sludge was accompanied by increased abundances of 12 operational taxonomic units (OTUs). The most prominent increase in abundances was recorded for OTUs affiliated with bacterial genera known to harbor denitrifiers. Among these were the Betaproteobacteria genera Thauera, which utilizes terpenes to fuel denitrification, and Comamonas, which was previously isolated from the digestion basin of the same system and is capable of growth on geosmin and MIB as sole carbon and energy sources. Thus far, denitrification has been associated with bacteria capable of utilizing terpenes other than geosmin and MIB. The significant increase in the abundance of denitrifying bacterial genera in sludge in which geosmin and MIB comprised only 0.06% of the total carbon content might indicate that such bacteria play a major role in the removal of these compounds in anoxic environments. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.
Schlesinger, S. ; Meshorer, E. Open Chromatin, Epigenetic Plasticity, and Nuclear Organization in Pluripotency. Developmental Cell 2019, 48, 135-150. Publisher's VersionAbstract
Pluripotent embryonic stem cells are considered to have open and accessible chromatin relative to differentiated cells. Schlesinger and Meshorer review chromatin and epigenetic features in 2i- versus serum-grown conditions to come to a clearer picture of the genuine characteristics of pluripotency as opposed to artifacts of culture condition. © 2019 Elsevier Inc. Pluripotent embryonic stem cells (ESCs) are considered to have open and accessible chromatin relative to differentiated cells. However, as many studies supporting these conclusions relied on ESCs grown in serum, it has been suggested that some of these features are the result of culture conditions, particularly as more recent work using GSK3/MEK inhibitors (“2i”) to mimic “ground-state” conditions of the pre-implantation blastocyst observed some altered epigenetic features. Here, we systematically review chromatin and epigenetic features in 2i- and serum-grown conditions to come to a clearer picture of what are genuine characteristics of pluripotency and what open chromatin features predict pluripotency. © 2019 Elsevier Inc.
Komsky-Elbaz, A. ; Saktsier, M. ; Biran, D. ; Argov-Argaman, N. ; Azaizeh, H. ; Landau, Y. S. ; Roth, Z. Atrazine-induced toxicity in goat spermatozoa is alleviated to some extent by polyphenol-enriched feed. Chemosphere 2019, 236. Publisher's VersionAbstract
Atrazine (ATZ) is one of the most extensively used herbicides to control growth of broadleaf and grassy weeds in crops. ATZ and its metabolites have deleterious effect on sperm quality. ATZ is also known for its ability to induce oxidative stress. Pistacia lentiscus (PL) is an evergreen shrub, with a high content of polyphenols in leaf extracts, with a known anti-inflammatory and antioxidant properties. The protective effect of PL or its extracts against ATZ-induced damage have not been yet evaluated. We examined the harmful effects of atrazine (ATZ) exposure on male reproductive system, using goat (Capra hircus) model spermatozoa and the protective effects of PL and PL ethanolic extract (PLE). In in-vivo experiments, male goats were fed a standard ration or one supplemented with 15 mg ATZ/kg body weight daily, for 6 months. Exposure to ATZ impaired the spermatozoa's morphology, viability, mitochondrial membrane potential and cell lipid composition. These alterations may in turn lead to reduced fertilization competence of the exposed spermatozoa. In an ex-vivo experiment, spermatozoa from male goats fed a standard ration or one supplemented with PL or PLE for 90 days and then were exposed to 1 μM ATZ or 10 μM of its major metabolite diaminochlorotriazine (DACT) through in-vitro capacitation. Prefeeding with PL or PLE partially attenuated the harmful effects of ATZ and DACT. Dietary supplementation with polyphenol-enriched feed can protect, to a certain extent, spermatozoa in males exposed to environmental toxicants. © 2019 Elsevier Ltd
Komsky-Elbaz, A. ; Zubov, A. ; Roth, Z. Effect of the herbicide atrazine and its major metabolite, DACT, on bovine sperm cryotolerance. Theriogenology 2019, 140, 117-123. Publisher's VersionAbstract
During freezing and thawing procedures, sperm are exposed to chemical and/or physical stressors that may cause adverse and harmful changes to sperm membranes. Accurate evaluation of the structural and functional integrity of fresh as well as cryopreserved sperm is highly important in predicting sperm fertilization capacity and success of artificial insemination (AI). The herbicide atrazine (ATZ) and its major metabolite, diaminochlorotriazine (DACT) are considered a ubiquitous environmental contaminants and endocrine disruptors, which deleteriously effect sperm function. Taking into consideration possible damage caused by environmental contaminants to sperm membranes, additive effects during cryopreservation cannot be ruled out. The aim of the current study was to evaluate the effect of ATZ (0.1 or 1 μM) and DACT (1 or 10 μM) exposure during or after cryopreservation on bovine sperm cryotolerance. Sperm membrane integrity and functionality were evaluated using fluorimetric probes: (1) double-stranded DNA was examined by 4′,6-diamidino-2-phenylindole; (2) plasma membrane integrity was examined by propidium iodide; (3) acrosome reaction (AR) was examined by fluorescein isothiocyanate-conjugated Pisum sativum agglutinin; mitochondrial membrane potential (ΔΨm) was examined by 5,5′,6,6′-tetra-chloro-1,1′,3,3′-tetraethylbenzimidazolyl carbocyanine iodide fluorescent probe. The findings demonstrate, that exposure of sperm to ATZ (0.1 or 1 μM) or DACT (1 or 10 μM) during cryopreservation increased the proportion of dead sperm relative to the control (P < 0.09); exposure to DACT (1 or 10 μM) increased ΔΨm (P < 0.03). Neither ATZ nor DACT affected spontaneous AR. In contrast, the proportion of sperm with Ca++ ionophore-induced AR was lower after exposure to 1 μM DACT (P < 0.05). Following freezing and thawing procedures, exposing sperm to 1 μM ATZ increased the proportion of dead sperm relative to the control (P < 0.05), but had no significant effect on sperm ΔΨm or AR. In conclusion, exposing sperm to endocrine-disrupting chemicals such as ATZ or DACT during cryopreservation reduces sperm cryotolerance and resistance post-thawing. © 2019
Wolfenson, D. ; Roth, Z. Impact of heat stress on cow reproduction and fertility. Animal Frontiers 2019, 9 32-38. Publisher's Version
Basavaraja, R. ; Madusanka, S. T. ; Drum, J. N. ; Shrestha, K. ; Farberov, S. ; Wiltbank, M. C. ; Sartori, R. ; Meidan, R. Interferon-Tau Exerts Direct Prosurvival and Antiapoptotic Actions in Luteinized Bovine Granulosa Cells. Scientific Reports 2019, 9. Publisher's VersionAbstract
Interferon-tau (IFNT), serves as a signal to maintain the corpus luteum (CL) during early pregnancy in domestic ruminants. We investigated here whether IFNT directly affects the function of luteinized bovine granulosa cells (LGCs), a model for large-luteal cells. Recombinant ovine IFNT (roIFNT) induced the IFN-stimulated genes (ISGs; MX2, ISG15, and OAS1Y). IFNT induced a rapid and transient (15–45 min) phosphorylation of STAT1, while total STAT1 protein was higher only after 24 h. IFNT treatment elevated viable LGCs numbers and decreased dead/apoptotic cell counts. Consistent with these effects on cell viability, IFNT upregulated cell survival proteins (MCL1, BCL-xL, and XIAP) and reduced the levels of gamma-H2AX, cleaved caspase-3, and thrombospondin-2 (THBS2) implicated in apoptosis. Notably, IFNT reversed the actions of THBS1 on cell viability, XIAP, and cleaved caspase-3. Furthermore, roIFNT stimulated proangiogenic genes, including FGF2, PDGFB, and PDGFAR. Corroborating the in vitro observations, CL collected from day 18 pregnant cows comprised higher ISGs together with elevated FGF2, PDGFB, and XIAP, compared with CL derived from day 18 cyclic cows. This study reveals that IFNT activates diverse pathways in LGCs, promoting survival and blood vessel stabilization while suppressing cell death signals. These mechanisms might contribute to CL maintenance during early pregnancy. © 2019, The Author(s).
Meir, Y. A. B. ; Nikbachat, M. ; Portnik, Y. ; Jacoby, S. ; Levit, H. ; Bikel, D. ; Adin, G. ; Moallem, U. ; Miron, J. ; Mabjeesh, S. ; et al. Dietary restriction improved feed efficiency of inefficient lactating cows. Journal of Dairy Science 2019, 102, 8898-8906. Publisher's VersionAbstract
The aim of this study was to reduce voluntary dry matter intake (DMI) to increase feeding efficiency of preclassified inefficient (INE) dairy cows through restricted feeding. We studied the effects of dietary restriction on eating behavior, milk and energy-corrected milk (ECM) production, in vivo digestibility, energy balance, and measures of feed efficiency [residual feed intake (RFI) and ECM/DMI]. Before the experiment, 12 pairs of cows were classified as INE. The 2 dietary treatments consisted of ad libitum feeding versus restricted feeding of the same total mixed ration containing 36.5% roughage. Inefficient cows fed the restricted total mixed ration had a shorter eating time and lower meal and visit frequency, but a similar rate of eating, meal size, and meal duration compared with INE cows fed ad libitum. Compared with the INE cows fed ad libitum, restricted INE cows had 12.8% lower intake, their dry matter and neutral detergent fiber digestibility remained similar, and their ECM yield was 5.3% lower. Feed efficiency, measured as RFI, ECM/DMI, and net energy retained divided by digestible energy intake, was improved in the restricted INE cows as compared with the ad libitum cows. Our results show that moderate DMI restriction has the potential to improve feed efficiency of preclassified INE cows. © 2019 American Dairy Science Association
Meir, Y. A. B. ; Nikbachat, M. ; Jacoby, S. ; Portnik, Y. ; Levit, H. ; Elazary, A. K. ; Gershon, E. ; Adin, G. ; Zinder, M. C. ; Shabtay, A. ; et al. Effect of lactation trimester and parity on eating behavior, milk production and efficiency traits of dairy cows. Animal 2019, 13, 1736-1743. Publisher's VersionAbstract
There is absence knowledge about the effects of lactation trimester and parity on eating behavior, production and efficiency of dairy cows. Objective of this study was to identify and characterize in 340 dairy cows, the 20% high efficient (HE), 20% low efficient (LE) and 60% mid efficient (ME) cows according to their individual residual feed intake (RFI) values, within and between lactation trimesters and between 1st and 2nd parities. Efficiency effect within each lactation trimester, was exhibited in daily dry matter intake (DMI), eating rate and meal size, that were the highest in LE cows, moderate in the ME cows and lowest in the HE group. Daily eating time, meal frequency, yields of milk and energy-corrected milk (ECM) and BW were similar in the three efficiency groups within each trimester. The lower efficiency of the LE cows in each trimester attributes to their larger metabolic energy intake, heat production and energy losses. In subgroup of 52 multiparous cows examined along their 1st and 2nd trimesters, milk and ECM production, DMI, eating behavior and efficiency traits were similar with high Pearson's correlation (r=0.78 to 0.89) between trimesters. In another subgroup of 42 multiparous cows measured at their 2nd and 3rd trimesters, milk and ECM yield, DMI and eating time were reduced (P<0.01) at the 3rd trimester, but eating rate, meal frequency and meal size remained similar with high Pearson's correlation (r=0.74 to 0.88) between trimesters. In subgroup of 26 cows measured in 1st and 2nd parities, DMI, BW, milk and ECM yield, and ECM/DMI increased in the 2nd lactation, but eating behavior and RFI traits were similar in both parities. These findings encourage accurate prediction of DMI based on a model that includes eating behavior parameters, together with individual measurement of ECM production. This can be further used to identify HE cows in commercial herd, a step necessary for potential genetic selection program aimed to improve herd efficiency. © The Animal Consortium 2019.
Mizrahi, N. ; Gilon, C. ; Atre, I. ; Ogawa, S. ; Parhar, I. S. ; Levavi-Sivan, B. Deciphering direct and indirect effects of neurokinin B and GnRH in the brain-pituitary axis of tilapia. Frontiers in Endocrinology 2019, 10. Publisher's VersionAbstract
Neurokinin B (NKB) and its cognate receptor (NK3R) are emerging as important components of the neuroendocrine regulation of reproduction. Unlike mammalian tac3, which encodes only one mature peptide (namely NKB), two mature peptides are predicted for each tac3 gene in fish and frogs. Therefore, it was designated as Neurokinin F (NKF). Hormone analogs with high and long-lasting biological activity are important tools for physiological and biological research; however, the availability of piscine-specific analogs is very limited. Therefore, we have developed specific NKB and NKF analogs based on the structure of the mammalian NKB analog–senktide. These analogs, specifically designed for longer half-lives by methylation of proteolysis sites, exhibited activity equal to those of the native NKB and NKF in short-term signal-transduction assays of tilapia NKB receptors. However, the analogs were found to be able to significantly increase the release of luteinizing hormone (LH), follicle stimulating hormone (FSH) and growth hormone (GH) in tilapia, as fast as 1 h after intraperitoneal (IP) injection. The impact of the analogs on LH and FSH secretion lasted longer compared to the effect of native peptides and salmon GnRH analog (sGnRHa). In addition, we harvested pituitaries 24 h post injection and measured LH, FSH and GH mRNA synthesis. Both analogs elevated mRNA levels of LH and GH, but only NKB analog increased FSH mRNA levels in the pituitary and all GnRH forms in the brain. NKB receptors were co-localized with all three types the GnRH neurons in tilapia brain in situ. We previously showed a direct effect of NKB at the pituitary level, and these new results suggest that the stronger impact of the NKB analog on GTH release is also due to an indirect effect through the activation of GnRH neurons. These results suggest that novel synthetic NKB analogs may serve as a tool for both research and agricultural purposes. Finally, the biological activity and regulatory role of NKB in tilapia brain and pituitary suggest that the NKB/NKBR system in fish is an important reproductive regulator in a similar way to the kisspeptin system in mammals. Copyright © 2019 Mizrahi, Gilon, Atre, Ogawa, Parhar and Levavi-Sivan. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
Hollander-Cohen, L. ; Böhm, B. ; Hausken, K. ; Levavi-Sivan, B. Ontogeny of the specificity of gonadotropin receptors and gene expression in carp. Endocrine Connections 2019, 8 1433-1446. Publisher's VersionAbstract
The pituitary gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), are the principle endocrine drivers of reproductive processes in the gonads of jawed vertebrates. Canonically, FSH recruits and maintains selected ovarian follicles for maturation and LH induces the stages of germinal vesicle breakdown and ovulation. In mammals, LH and FSH specifically activate cognate G-protein-coupled receptors that affect the proteins involved in steroidogenesis, protein hormone synthesis, and gametogenesis. This dual-gonadotropin model also exists in some fish species, but not in all. In fact, due to their diverse number of species, extended number of ecological niches, and remarkably flexible reproductive strategies, fish are appropriate as models to understand the co-evolution of gonadotropins and their receptors. In this study, we cloned and characterized the expression profile over the final stages of ovarian maturation of carp (Cyprinus carpio) LHCGR and FSHR. Expression of both gonadotropin receptors increased in the later stage of early vitellogenesis, suggesting that both LH and FSH play a role in the development of mature follicles. We additionally tested the activation of cLHCGR and cFSHR using homologous and heterologous recombinant gonadotropins in order to gain insight into an evolutionary model of permissive gonadotropin receptor function. These data suggest that carp (Cyprinus carpio) gonad development and maturation depends on a specific gonadotropin profile that does not reflect the temporally distinct dual-gonadotropin model observed in salmonids or mammals, and that permissive gonadotropin receptor activation is a specific feature of Ostariophysi, not all teleosts. © 2019 The authors.
Hausken, K. ; Levavi-Sivan, B. Synteny and phylogenetic analysis of paralogous thyrostimulin beta subunits (GpB5) in vertebrates. PLoS ONE 2019, 14. Publisher's VersionAbstract
At some point early in the vertebrate lineage, two whole genome duplication events (1R, 2R) took place that allowed for the diversification and sub-/neo-functionalization of the glycoprotein hormones (GpHs). All jawed vertebrates possess the GpHs luteinizing hormone (LH), follicle stimulating hormone (FSH), and thyroid stimulating hormone (TSH), each of which are heterodimers with a common alpha subunit and unique beta subunits. In 2002, a novel glycoprotein hormone named thyrostimulin was described to have unique GpA2 and GpB5 subunits that were homologous to the vertebrate alpha and beta subunits. The presence of GpA2 and GpB5 in representative protostomes and deuterostomes indicates their ancestry in the GpH family. There are several reports of GpH subunit evolution, but none have included GpA2 and GpB5 for species in each major vertebrate class. Thus, we addressed the ancestry of two paralogous GpB5 subunits (GpB5a and GpB5b) that were previously only recognized in two teleost species. Our search for orthologous GpB5a and GpB5b sequences in representative vertebrates and phylogenetic analysis, in addition to the currently published evolutionary scenarios of the GpH family, supports that GpB5a and GpB5b are paralogs that arose from the first vertebrate whole genome duplication event (1R). Syntenic analysis supports lineage specific losses of GpB5a in chondrichthyes, basal actinopterygians, and tetrapods, and retention in coelacanth and teleosts. Additionally, we were unable to identify GpA2 transcripts from tilapia mRNA, suggesting that this species does not produce heterodimeric thyrostimulin. While the conserved or even species-specific functional role of thyrostimulin or its individual subunits are still unknown in vertebrates, the analyses presented here provide context for future studies on the functional divergence of the GpH family. © 2019 Hausken, Levavi-Sivan. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Forkosh, O. ; Karamihalev, S. ; Roeh, S. ; Alon, U. ; Anpilov, S. ; Touma, C. ; Nussbaumer, M. ; Flachskamm, C. ; Kaplick, P. M. ; Shemesh, Y. ; et al. Identity domains capture individual differences from across the behavioral repertoire. Nature Neuroscience 2019, 22, 2023-2028. Publisher's VersionAbstract
Personality traits can offer considerable insight into the biological basis of individual differences. However, existing approaches toward understanding personality across species rely on subjective criteria and limited sets of behavioral readouts, which result in noisy and often inconsistent outcomes. Here we introduce a mathematical framework for describing individual differences along dimensions with maximum consistency and discriminative power. We validate this framework in mice, using data from a system for high-throughput longitudinal monitoring of group-housed male mice that yields a variety of readouts from across the behavioral repertoire of individual animals. We demonstrate a set of stable traits that capture variability in behavior and gene expression in the brain, allowing for better-informed mechanistic investigations into the biology of individual differences. © 2019, The Author(s), under exclusive licence to Springer Nature America, Inc.
Embregts, C. W. E. ; Tadmor-Levi, R. ; Veselý, T. ; Pokorová, D. ; David, L. ; Wiegertjes, G. F. ; Forlenza, M. Intra-muscular and oral vaccination using a Koi Herpesvirus ORF25 DNA vaccine does not confer protection in common carp (Cyprinus carpio L.). Fish and Shellfish Immunology 2019, 85, 90-98. Publisher's VersionAbstract
Koi Herpes Virus (KHV or Cyprinid Herpesvirus 3, CyHV-3) is among the most threatening pathogens affecting common carp production as well as the highly valuable ornamental koi carp. To date, no effective commercial vaccine is available for worldwide use. A previous study reported that three intramuscular injections with an ORF25-based DNA vaccine, led to the generation of neutralizing antibodies and conferred significant protection against an intraperitoneal challenge with KHV. In the present study, we set out to optimize an ORF25-based DNA vaccination protocol that required fewer injections and would confer protection upon a challenge that better resembled the natural route of infection. To this end, ORF25 was cloned in pcDNA3 either as a soluble protein or as a full-length transmembrane GFP-fusion protein. We tested our ORF25-based DNA vaccines in multiple vaccination trials using different doses, vaccination routes (i.m. injection and oral gavage) and challenge methods (bath and cohabitation). Furthermore, we analysed local and systemic responses to the i.m. injected DNA vaccine through histological and RT-qPCR analysis. We observed a strong protection when fish received three injections of either of the two DNA vaccines. However, this protection was observed only after bath challenge and not after cohabitation challenge. Furthermore, protection was insufficient when fish received one injection only, or received the plasmid orally. The importance of choosing a challenge model that best reflects the natural route of infection and the possibility to include additional antigens in future DNA vaccination strategies against KHV will be discussed. © 2018 The Author(s)
Golani, D. ; Sonin, O. ; Snovsky, G. ; David, L. ; Tadmor-Levi, R. The occurrence of the peacock bass (Cichla kelberi Kullander and Ferreira, 2006) in Lake Kinneret (Sea of Galilee), Israel. BioInvasions Records 2019, 8 706-711. Publisher's VersionAbstract
A specimen of Cichla kelberi Kullander and Ferreira, 2006 was captured for the first time from Lake Kinneret (Sea of Galilee or Lake Tiberias), Israel. Its identification was made by morphological and molecular means. Although importation of this species to Israel is prohibited, commercial importers have smuggled juveniles as aquarium fish. The introduction vector of the specimen in Lake Kinneret is probably due to release or escape from the aquariums of hobbyists. © Golani et al.
Komsky-Elbaz, A. ; Saktsier, M. ; Biran, D. ; Argov-Argaman, N. ; Azaizeh, H. ; Landau, Y. S. ; Roth, Z. Atrazine-induced toxicity in goat spermatozoa is alleviated to some extent by polyphenol-enriched feed. Chemosphere 2019, 236. Publisher's VersionAbstract
Atrazine (ATZ) is one of the most extensively used herbicides to control growth of broadleaf and grassy weeds in crops. ATZ and its metabolites have deleterious effect on sperm quality. ATZ is also known for its ability to induce oxidative stress. Pistacia lentiscus (PL) is an evergreen shrub, with a high content of polyphenols in leaf extracts, with a known anti-inflammatory and antioxidant properties. The protective effect of PL or its extracts against ATZ-induced damage have not been yet evaluated. We examined the harmful effects of atrazine (ATZ) exposure on male reproductive system, using goat (Capra hircus) model spermatozoa and the protective effects of PL and PL ethanolic extract (PLE). In in-vivo experiments, male goats were fed a standard ration or one supplemented with 15 mg ATZ/kg body weight daily, for 6 months. Exposure to ATZ impaired the spermatozoa's morphology, viability, mitochondrial membrane potential and cell lipid composition. These alterations may in turn lead to reduced fertilization competence of the exposed spermatozoa. In an ex-vivo experiment, spermatozoa from male goats fed a standard ration or one supplemented with PL or PLE for 90 days and then were exposed to 1 μM ATZ or 10 μM of its major metabolite diaminochlorotriazine (DACT) through in-vitro capacitation. Prefeeding with PL or PLE partially attenuated the harmful effects of ATZ and DACT. Dietary supplementation with polyphenol-enriched feed can protect, to a certain extent, spermatozoa in males exposed to environmental toxicants. © 2019 Elsevier Ltd