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Bishop CV, Selvaraj V, Townson DH, Pate JL, Wiltbank MC. History, insights, and future perspectives on studies into luteal function in cattle. J Anim Sci 2022; 100:skac143. [PMID: 35772753 PMCID: PMC9246667 DOI: 10.1093/jas/skac143] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 04/12/2022] [Indexed: 12/12/2022] Open
Abstract
The corpus luteum (CL) forms following ovulation from the remnant of the Graafian follicle. This transient tissue produces critical hormones to maintain pregnancy, including the steroid progesterone. In cattle and other ruminants, the presence of an embryo determines if the lifespan of the CL will be prolonged to ensure successful implantation and gestation, or if the tissue will undergo destruction in the process known as luteolysis. Infertility and subfertility in dairy and beef cattle results in substantial economic loss to producers each year. In addition, this has the potential to exacerbate climate change because more animals are needed to produce high-quality protein to feed the growing world population. Successful pregnancies require coordinated regulation of uterine and ovarian function by the developing embryo. These processes are often collectively termed "maternal recognition of pregnancy." Research into the formation, function, and destruction of the bovine CL by the Northeast Multistate Project, one of the oldest continuously funded Hatch projects by the USDA, has produced a large body of evidence increasing our knowledge of the contribution of ovarian processes to fertility in ruminants. This review presents some of the seminal research into the regulation of the ruminant CL, as well as identifying mechanisms that remain to be completely validated in the bovine CL. This review also contains a broad discussion of the roles of prostaglandins, immune cells, as well as mechanisms contributing to steroidogenesis in the ruminant CL. A triadic model of luteolysis is discussed wherein the interactions among immune cells, endothelial cells, and luteal cells dictate the ability of the ruminant CL to respond to a luteolytic stimulus, along with other novel hypotheses for future research.
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Affiliation(s)
- Cecily V Bishop
- Department of Animal and Rangeland Sciences, College of Agricultural Sciences, Oregon State University, Corvallis, OR 97331, USA
| | - Vimal Selvaraj
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853, USA
| | - David H Townson
- Department of Animal and Veterinary Sciences, The University of Vermont, Burlington, VT 05405, USA
| | - Joy L Pate
- Department of Animal Science, Center for Reproductive Biology and Health, Pennsylvania State University, State College, PA 16802, USA
| | - Milo C Wiltbank
- Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA
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A review on inflammation and angiogenesis as key mechanisms involved in the pathogenesis of bovine cystic ovarian disease. Theriogenology 2022; 186:70-85. [DOI: 10.1016/j.theriogenology.2022.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 04/01/2022] [Accepted: 04/05/2022] [Indexed: 11/23/2022]
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Abdulrahman N, Fair T. Contribution of the immune system to follicle differentiation, ovulation and early corpus luteum formation. Anim Reprod 2019; 16:440-448. [PMID: 32435287 PMCID: PMC7234072 DOI: 10.21451/1984-3143-ar2019-0087] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Accepted: 07/25/2019] [Indexed: 12/30/2022] Open
Abstract
Much of what we know about the involvement of the immune system in periovulatory follicle differentiation, ovulation and subsequent formation of the corpus luteum in cattle is drawn from the findings of studies in several mammalian livestock species. By integrating published histological data from cattle, sheep and pigs and referring back to the more comprehensive knowledge bank that exists for mouse and humans we can sketch out the key cells of the immune system and the cytokines and growth factors that they produce that are involved in follicle differentiation and luteinization, ovulation and early follicle development. These contributions are reviewed and the key findings, discussed.
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Affiliation(s)
- Noof Abdulrahman
- School of Agriculture & Food Sciences, University College Dublin, Belfield, Dublin 4, Ireland.
| | - Trudee Fair
- School of Agriculture & Food Sciences, University College Dublin, Belfield, Dublin 4, Ireland.
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Poulsen LLC, Englund ALM, Wissing MLM, Yding Andersen C, Borup R, Grøndahl ML. Human granulosa cells function as innate immune cells executing an inflammatory reaction during ovulation: a microarray analysis. Mol Cell Endocrinol 2019; 486:34-46. [PMID: 30802528 DOI: 10.1016/j.mce.2019.02.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 01/16/2019] [Accepted: 02/18/2019] [Indexed: 02/07/2023]
Abstract
Ovulation has been compared to a local inflammatory reaction. We performed an in silico study on a unique, PCR validated, transcriptome microarray study to evaluate if known inflammatory mechanisms operate during ovulation. The granulosa cells were obtained in paired samples at two different time points during ovulation (just before and 36 hours after ovulation induction) from nine women receiving fertility treatment. A total of 259 genes related to inflammation became significantly upregulated during ovulation (2-80 fold, p<0.05), while specific leukocyte markers were absent. The genes and pathway analysis indicated NF-KB-, MAPK- and JAK/STAT signalling (p<1.0E-10) as the major pathways involved in danger recognition and cytokine signalling to initiate inflammation. Upregulated genes further encoded enzymes in eicosanoid production, chemo-attractants, coagulation factors, cell proliferation factors involved in tissue repair, and anti-inflammatory factors to resolve the inflammation again. We conclude that granulosa cells, without involvement from the innate immune system, can orchestrate ovulation as a complete sterile inflammatory reaction.
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Affiliation(s)
- Liv la Cour Poulsen
- Zealand Fertility Clinic, Zealand University Hospital, Lykkebækvej 14, 4600, Køge, Denmark.
| | | | | | - Claus Yding Andersen
- Laboratory of Reproductive Biology, University Hospital of Copenhagen, Rigshospitalet, Blegdamsvej 9, 2100, Copenhagen Ø, Denmark
| | - Rehannah Borup
- Center for Chromosome Stability, Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen N, Denmark
| | - Marie Louise Grøndahl
- Herlev Fertility Clinic, University Hospital of Copenhagen, Herlev and Gentofte Hospital, Herlev Ringvej 75, 2730, Herlev, Denmark
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Brodzki P, Brodzki A, Krakowski L, Dąbrowski R, Szczubiał M, Bochniarz M. Levels of selected cytokines and acute–phase proteins in the serum of dairy cows with cystic ovarian disease and those in follicular and luteal phases of normal ovarian cycle. Res Vet Sci 2019; 123:20-25. [DOI: 10.1016/j.rvsc.2018.12.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 11/09/2018] [Accepted: 12/17/2018] [Indexed: 11/26/2022]
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Braud M, Magee DA, Park SDE, Sonstegard TS, Waters SM, MacHugh DE, Spillane C. Genome-Wide microRNA Binding Site Variation between Extinct Wild Aurochs and Modern Cattle Identifies Candidate microRNA-Regulated Domestication Genes. Front Genet 2017; 8:3. [PMID: 28197171 PMCID: PMC5281612 DOI: 10.3389/fgene.2017.00003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 01/09/2017] [Indexed: 12/21/2022] Open
Abstract
The domestication of cattle from the now-extinct wild aurochs (Bos primigenius) involved selection for physiological and behavioral traits, with underlying genetic factors that remain largely unknown. Non-coding microRNAs have emerged as key regulators of the spatio-temporal expression of target genes controlling mammalian growth and development, including in livestock species. During the domestication process, selection of mutational changes in miRNAs and/or miRNA binding sites could have provided a mechanism to generate some of the traits that differentiate domesticated cattle from wild aurochs. To investigate this, we analyzed the open reading frame DNA sequence of 19,994 orthologous protein-coding gene pairs from extant Bos taurus genomes and a single extinct B. primigenius genome. We identified miRNA binding site polymorphisms in the 3′ UTRs of 1,620 of these orthologous genes. These 1,620 genes with altered miRNA binding sites between the B. taurus and B. primigenius lineages represent candidate domestication genes. Using a novel Score Site ratio metric we have ranked these miRNA-regulated genes according to the extent of divergence between miRNA binding site presence, frequency and copy number between the orthologous genes from B. taurus and B. primigenius. This provides an unbiased approach to identify cattle genes that have undergone the most changes in miRNA binding (i.e., regulation) between the wild aurochs and modern-day cattle breeds. In addition, we demonstrate that these 1,620 candidate domestication genes are enriched for roles in pigmentation, fertility, neurobiology, metabolism, immunity and production traits (including milk quality and feed efficiency). Our findings suggest that directional selection of miRNA regulatory variants was important in the domestication and subsequent artificial selection that gave rise to modern taurine cattle.
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Affiliation(s)
- Martin Braud
- Genetics and Biotechnology Lab, Plant and AgriBiosciences Research Centre, School of Natural Sciences, National University of Ireland Galway, University Road Galway, Ireland
| | - David A Magee
- Animal Genomics Laboratory, UCD School of Agriculture and Food Science, University College Dublin Dublin, Ireland
| | - Stephen D E Park
- IdentiGEN Ltd, Unit 2, Trinity Enterprise Centre Dublin, Ireland
| | | | - Sinead M Waters
- Animal and Bioscience Research Department, Animal and Grassland Research and Innovation Centre, Teagasc Dunsany, Ireland
| | - David E MacHugh
- Animal Genomics Laboratory, UCD School of Agriculture and Food Science, University College DublinDublin, Ireland; UCD Conway Institute of Biomolecular and Biomedical Research, University College DublinDublin, Ireland
| | - Charles Spillane
- Genetics and Biotechnology Lab, Plant and AgriBiosciences Research Centre, School of Natural Sciences, National University of Ireland Galway, University Road Galway, Ireland
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Fair T. The contribution of the maternal immune system to the establishment of pregnancy in cattle. Front Immunol 2015; 6:7. [PMID: 25674085 PMCID: PMC4309202 DOI: 10.3389/fimmu.2015.00007] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 01/07/2015] [Indexed: 11/13/2022] Open
Abstract
Immune cells play an integral role in affecting successful reproductive function. Indeed, disturbed or aberrant immune function has been identified as primary mechanisms behind infertility. In contrast to the extensive body of literature that exists for human and mouse, studies detailing the immunological interaction between the embryo and the maternal endometrium are quite few in cattle. Nevertheless, by reviewing the existing studies and extrapolating from sheep, pig, mouse, and human data, we can draw a reasonably comprehensive picture. Key contributions of immune cell populations include granulocyte involvement in follicle differentiation and gamete transfer, monocyte invasion of the peri-ovulatory follicle and their subsequent role in corpus luteum formation and the pivotal roles of maternal macrophage and dendritic cells in key steps of the establishment of pregnancy, particularly, the maternal immune response to the embryo. These contributions are reviewed in detail below and key findings are discussed.
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Affiliation(s)
- Trudee Fair
- School of Agriculture and Food Sciences, University College Dublin , Dublin , Ireland
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Tharmalingam-Jaikaran T, Walsh SW, McGettigan PA, Potter O, Struwe WB, Evans ACO, Rudd PM, Carrington SD. N-glycan profiling of bovine follicular fluid at key dominant follicle developmental stages. Reproduction 2014; 148:569-80. [DOI: 10.1530/rep-14-0035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Follicular fluid (FF), an important microenvironment for the development of oocytes, contains many proteins that are glycosylated withN-linked glycans. This study aimed i) to present an initial analysis of theN-linked glycan profile of bovine FF using hydrophilic interaction liquid chromatography, anion exchange chromatography, high performance liquid chromatography (HPLC)-based separations and subsequent liquid chromatography–mass spectrometry/mass spectrometry analysis; ii) to determine differences in theN-glycan profile between FF from dominant and subordinate follicles from dairy heifers and lactating dairy cows and iii) to identify alterations in theN-glycan profile of FF during preovulatory follicle development using newly selected, differentiated (preovulatory) and luteinised dominant follicles from dairy heifers and lactating cows. We found that the majority of glycans on bovine FF are based on biantennary hypersialylated structures, where the glycans are sialylated on both the galactose andN-acetylglucosamine terminal sugars. A comparison of FFN-glycans from cows and heifers indicated higher levels of nonsialylated glycans with a lower proportion of sialylated glycans in cows than in heifers. Overall, as the follicle develops from Selection, Differentiation and Luteinisation in both cows and heifers, there is an overall decrease in sialylated structures on FFN-glycans.
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Donadeu FX, Fahiminiya S, Esteves CL, Nadaf J, Miedzinska K, McNeilly AS, Waddington D, Gérard N. Transcriptome profiling of granulosa and theca cells during dominant follicle development in the horse. Biol Reprod 2014; 91:111. [PMID: 25253738 DOI: 10.1095/biolreprod.114.118943] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Several aspects of equine ovarian physiology are unique among domestic species. Moreover, follicular growth patterns are very similar between horses and humans. This study aimed to characterize, for the first time, global gene expression profiles associated with growth and preovulatory (PO) maturation of equine dominant follicles. Granulosa cells (GCs) and theca interna cells (TCs) were harvested from follicles (n = 5) at different stages of an ovulatory wave in mares corresponding to early dominance (ED; diameter ≥22 mm), late dominance (LD; ≥33 mm) and PO stage (34 h after administration of crude equine gonadotropins at LD stage), and separately analyzed on a horse gene expression microarray, followed by validation using quantitative PCR and immunoblotting/immunohistochemistry. Numbers of differentially expressed transcripts (DETs; ≥2-fold; P < 0.05) during the ED-LD and LD-PO transitions were 546 and 2419 in GCs and 5 and 582 in TCs. The most prominent change in GCs was the down-regulation of transcripts associated with cell division during both ED-LD and LD-PO. In addition, DET sets during LD-PO in GCs were enriched for genes involved in cell communication/adhesion, antioxidation/detoxification, immunity/inflammation, and cholesterol biosynthesis. In contrast, the largest change in TCs during the LD-PO transition was an up-regulation of genes involved in immune activation, with other DET sets mapping to GPCR/cAMP signaling, lipid/amino acid metabolism, and cell proliferation/survival and differentiation. In conclusion, distinct expression profiles were identified between growing and PO follicles and, particularly, between GCs and TCs within each stage. Several DETs were identified that have not been associated with follicle development in other species.
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Affiliation(s)
- F Xavier Donadeu
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, United Kingdom
| | - Somayyeh Fahiminiya
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, United Kingdom INRA and CNRS, UMR 6175 Physiologie de la Reproduction et des Comportements, Nouzilly, France Université François Rabelais de Tours, UMR 6175 Physiologie de la Reproduction et des Comportements, Tours, France
| | - Cristina L Esteves
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, United Kingdom
| | - Javad Nadaf
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, United Kingdom
| | - Katarzyna Miedzinska
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, United Kingdom
| | - Alan S McNeilly
- The Queen's Medical Research Institute, MRC Centre for Reproductive Health, Edinburgh, United Kingdom
| | - David Waddington
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, United Kingdom
| | - Nadine Gérard
- INRA and CNRS, UMR 6175 Physiologie de la Reproduction et des Comportements, Nouzilly, France Université François Rabelais de Tours, UMR 6175 Physiologie de la Reproduction et des Comportements, Tours, France Haras Nationaux, UMR 6175 Physiologie de la Reproduction et des Comportements, Nouzilly, France
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O'Doherty AM, O'Gorman A, al Naib A, Brennan L, Daly E, Duffy P, Fair T. Negative energy balance affects imprint stability in oocytes recovered from postpartum dairy cows. Genomics 2014; 104:177-85. [PMID: 25084396 DOI: 10.1016/j.ygeno.2014.07.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 07/14/2014] [Accepted: 07/15/2014] [Indexed: 12/27/2022]
Abstract
Ovarian follicle development in post-partum, high-producing dairy cows, occurs in a compromised endogenous metabolic environment (referred to as negative energy balance, NEB). Key events that occur during oocyte/follicle growth, such as the vital process of genomic imprinting, may be detrimentally affected by this altered ovarian environment. Imprinting is crucial for placental function and regulation of fetal growth, therefore failure to establish and maintain imprints during oocyte growth may contribute to early embryonic loss. Using ovum pick-up (OPU), oocytes and follicular fluid samples were recovered from cows between days 20 and 115 post-calving, encompassing the NEB period. In a complimentary study, cumulus oocyte complexes were in vitro matured under high non-esterified fatty acid (NEFA) concentrations and in the presence of the methyl-donor S-adenosylmethionine (SAM). Pyrosequencing revealed the loss of methylation at several imprinted loci in the OPU derived oocytes. The loss of DNA methylation was observed at the PLAGL1 locus in oocytes, following in vitro maturation (IVM) in the presence of elevated NEFAs and SAM. Finally, metabolomic analysis of postpartum follicular fluid samples revealed significant differences in several branched chain amino acids, with fatty acid profiles bearing similarities to those characteristic of lactating dairy cows. These results provide the first evidence that (1) the postpartum ovarian environment may affect maternal imprint acquisition and (2) elevated NEFAs during IVM can lead to the loss of imprinted gene methylation in bovine oocytes.
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Affiliation(s)
- Alan M O'Doherty
- School of Agriculture & Food Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Aoife O'Gorman
- School of Agriculture & Food Science, University College Dublin, Belfield, Dublin 4, Ireland; Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Abdullah al Naib
- Lyons Research Farm, University College Dublin, Belfield, Dublin 4, Ireland
| | - Lorraine Brennan
- School of Agriculture & Food Science, University College Dublin, Belfield, Dublin 4, Ireland; Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Edward Daly
- Lyons Research Farm, University College Dublin, Belfield, Dublin 4, Ireland
| | - Pat Duffy
- Lyons Research Farm, University College Dublin, Belfield, Dublin 4, Ireland
| | - Trudee Fair
- School of Agriculture & Food Science, University College Dublin, Belfield, Dublin 4, Ireland.
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Weikard R, Hadlich F, Kuehn C. Identification of novel transcripts and noncoding RNAs in bovine skin by deep next generation sequencing. BMC Genomics 2013; 14:789. [PMID: 24225384 PMCID: PMC3833843 DOI: 10.1186/1471-2164-14-789] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Accepted: 11/04/2013] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Deep RNA sequencing (RNAseq) has opened a new horizon for understanding global gene expression. The functional annotation of non-model mammalian genomes including bovines is still poor compared to that of human and mouse. This particularly applies to tissues without direct significance for milk and meat production, like skin, in spite of its multifunctional relevance for the individual. Thus, applying an RNAseq approach, we performed a whole transcriptome analysis of pigmented and nonpigmented bovine skin to describe the comprehensive transcript catalogue of this tissue. RESULTS A total of 39,577 unique primary skin transcripts were mapped to the bovine reference genome assembly. The majority of the transcripts were mapped to known transcriptional units (65%). In addition to the reannotation of known genes, a substantial number (10,884) of unknown transcripts (UTs) were discovered, which had not previously been annotated. The classification of UTs was based on the prediction of their coding potential and comparative sequence analysis, subsequently followed by meticulous manual curation. The classification analysis and experimental validation of selected UTs confirmed that RNAseq data can be used to amend the annotation of known genes by providing evidence for additional exons, untranslated regions or splice variants, by approving genes predicted in silico and by identifying novel bovine loci. A large group of UTs (4,848) was predicted to potentially represent long noncoding RNA (lncRNA). Predominantly, potential lncRNAs mapped in intergenic chromosome regions (4,365) and therefore, were classified as potential intergenic lncRNA. Our analysis revealed that only about 6% of all UTs displayed interspecies conservation and discovered a variety of unknown transcripts without interspecies homology but specific expression in bovine skin. CONCLUSIONS The results of our study demonstrate a complex transcript pattern for bovine skin and suggest a possible functional relevance of novel transcripts, including lncRNA, in the modulation of pigmentation processes. The results also indicate that the comprehensive identification and annotation of unknown transcripts from whole transcriptome analysis using RNAseq data remains a tremendous future challenge.
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Affiliation(s)
- Rosemarie Weikard
- Leibniz Institute for Farm Animal Biology (FBN), Institute of Genome Biology, Dummerstorf 18196, Germany.
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Walusimbi SS, Pate JL. Physiology and Endocrinology Symposium: role of immune cells in the corpus luteum. J Anim Sci 2013; 91:1650-9. [PMID: 23422006 DOI: 10.2527/jas.2012-6179] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The immune system is essential for optimal function of the reproductive system. The corpus luteum (CL) is an endocrine organ that secretes progesterone, which is responsible for regulating the length of the estrous cycle, and for the establishment and maintenance of pregnancy in mammals. This paper reviews literature that addresses 2 areas; i) how immune cells are recruited to the CL, and ii) how immune cells communicate with luteal cells to affect the formation, development, and regression of the CL. Immune cells, primarily recruited to the ovulatory follicle from lymphoid organs after the LH surge, facilitate ovulation and populate the developing CL. During the luteal phase, changes in the population of macrophages, eosinophils, neutrophils, and T lymphocytes occur at critical functional stages of the CL. In addition to their role in facilitating ovulation, immune cells may have an important role in luteal function. Evidence shows that cytokines secreted by immune cells modulate both luteotropic and luteolytic processes. However, the decision to pursue either function may depend on the environment provided by luteal cells. It is suggested that understanding the role immune cells play could lead to identification of new strategies to improve fertility in dairy cattle and other species.
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Affiliation(s)
- S S Walusimbi
- Center for Reproductive Biology and Health, Department of Animal Science, Pennsylvania State University, University Park 16802, USA
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