ABSTRACT
The bovine pre-implantation embryo secretes bioactive molecules from early development stages, but effects on endometrial function are reported to start only after elongation. Here, we interrogated spatially defined regions of the endometrium transcriptome for responses to a day 7 embryo in vivo. We hypothesize that exposure to an embryo changes the abundance of specific transcripts in the cranial region of the pregnant uterine horn. Endometrium was collected from the uterotubal junction (UTJ), anterior (IA), medial (IM) and posterior (IP) regions of the uterine horn ipsilateral to the CL 7 days after estrus from sham-inseminated (Con) or artificially inseminated, confirmed pregnant (Preg) cows. Abundance of 86 transcripts was evaluated by qPCR using a microfluidic platform. Abundance of 12 transcripts was modulated in the Preg endometrium, including classical interferon-stimulated genes (ISG15, MX1, MX2 and OAS1Y), prostaglandin biosynthesis genes (PTGES, HPGD and AKR1C4), water channel (AQP4) and a solute transporter (SLC1A4) and this was in the UTJ and IA mainly. Additionally, for 71 transcripts, abundance varied according to region of the reproductive tract. Regulation included downregulation of genes associated with proliferation (IGF1, IGF2, IGF1R and IGF2R) and extracellular matrix remodeling (MMP14, MMP19 and MMP2) and upregulation of anti-adhesive genes (MUC1) in the cranial regions of uterine horn. Physical proximity to the embryo provides paracrine regulation of endometrial function. Embryo-independent regulation of the endometrial transcriptome may support subsequent stages of embryo development, such as elongation and implantation. We speculate that successful early embryo-dependent and -independent programming fine-tune endometrial functions that are important for maintenance of pregnancy in cattle.
Subject(s)
Embryo Implantation/genetics , Endometrium/metabolism , Gene Expression Regulation, Developmental , Pregnancy, Animal , RNA, Messenger/genetics , Transcriptome , Animals , Cattle , Embryo, Mammalian , Embryonic Development/genetics , Endometrium/growth & development , Estrus/physiology , Female , Gene Expression Profiling , Gene Ontology , Molecular Sequence Annotation , Pregnancy , RNA, Messenger/metabolismABSTRACT
Em bovinos de corte, ocorre significativa mortalidade embrionária durante as três primeiras semanas degestação. Durante esse período, o desenvolvimento de zigoto a concepto depende exclusivamente das secreçõesovidutais e uterinas. O processo de secreção, bem como a qualidade dessas secreções são programados pelaexposição sequencial do trato reprodutivo ao estradiol (E2) durante o proestro/estro e à progesterona (P4)durante o diestro inicial. Estratégias visando a otimização da qualidade dos ambientes ovidutal e uterino para odesenvolvimento embrionário serão discutidas e incluem o gerenciamento do crescimento do folículo pré-ovulatório, a suplementação de E2 no proestro, a suplementação de P4 no diestro inicial e combinações entreelas. Ao final, discute-se a intrigante possibilidade do embrião bovino programar o funcionamento doendométrio já na primeira semana de gestação.(AU)
In beef cattle, there is significant embryonic mortality during the three initial weeks of pregnancy.During this period, the development from zygote to conceptus depends exclusively on secretions from the oviductand uterus. The process of secretion as well as the quality of such secretions are programmed by the sequentialexposure of the reproductive tract to estradiol (E2), during proestrus and estrus, and to progesterone (P4),during early diestrus. Strategies that aim to optimize the quality of the oviductal and the uterine environmentstowards embryo development are discussed. Strategies include managing growth of the pre-ovulatory follicle,E2 supplementation at proestrus, P4 supplementation during early diestrus and combinations. Last but not least,we discuss the intriguing possibility of bovine embryo programming endometrial function as early as the firstweek of gestation.(AU)
Subject(s)
Animals , Female , Cattle , Cattle/anatomy & histology , Cattle/embryology , Fertility , Estradiol , ProgesteroneABSTRACT
Em bovinos de corte, ocorre significativa mortalidade embrionária durante as três primeiras semanas degestação. Durante esse período, o desenvolvimento de zigoto a concepto depende exclusivamente das secreçõesovidutais e uterinas. O processo de secreção, bem como a qualidade dessas secreções são programados pelaexposição sequencial do trato reprodutivo ao estradiol (E2) durante o proestro/estro e à progesterona (P4)durante o diestro inicial. Estratégias visando a otimização da qualidade dos ambientes ovidutal e uterino para odesenvolvimento embrionário serão discutidas e incluem o gerenciamento do crescimento do folículo pré-ovulatório, a suplementação de E2 no proestro, a suplementação de P4 no diestro inicial e combinações entreelas. Ao final, discute-se a intrigante possibilidade do embrião bovino programar o funcionamento doendométrio já na primeira semana de gestação.
In beef cattle, there is significant embryonic mortality during the three initial weeks of pregnancy.During this period, the development from zygote to conceptus depends exclusively on secretions from the oviductand uterus. The process of secretion as well as the quality of such secretions are programmed by the sequentialexposure of the reproductive tract to estradiol (E2), during proestrus and estrus, and to progesterone (P4),during early diestrus. Strategies that aim to optimize the quality of the oviductal and the uterine environmentstowards embryo development are discussed. Strategies include managing growth of the pre-ovulatory follicle,E2 supplementation at proestrus, P4 supplementation during early diestrus and combinations. Last but not least,we discuss the intriguing possibility of bovine embryo programming endometrial function as early as the firstweek of gestation.