Some Recent Findings
Blastocyst to Early Gastrulation Stages
Bovine stem cell marker expression
- Fetal age assessment for Holstein cattle "The objectives of this study were to investigate the correlation between fetal age and morphological features of bovine Holstein fetuses and to evaluate the use of these features alone and in combination with fetometric measurements to predict fetal age. We collected fetuses from 274 pregnant Holstein cows with recorded insemination dates slaughtered at a Danish abattoir. Gender, teeth development, occurrence of pigmentation, coat, tactile hair and other morphological features were recorded along with CRL, head width, head length and body weight (BW). The gestational length was calculated based on recorded insemination and slaughter dates, and coefficients of variation (R2) were determined for all recorded variables. Notably, the highest R2 was recorded for head length (0.985) followed by CRL (0.979) and head width (0.974). The categorical (morphological) variables were less informative. When used in multivariable models, they did offer statistically significance, but for practical purposes, limited additional information. A multivariable model including the fetometric variables head length and width in combination with CRL resulted in R2 = 0.99 with predictions that were roughly within +/- 11-12 days in 95% of cases. We conclude that the model based on the fetometric variables only provided the most precise predictions, while combination with morphological features such as eruption of teeth, pigmentation and coat mostly increased the width of the prediction intervals."
- Role of ROCK Signaling in Formation of the Trophectoderm of the Bovine Preimplantation Embryo "Rho-associated coiled-coil containing protein kinases (ROCK1 and ROCK2) are activated by binding to RHO GTPases and phosphorylate a variety of downstream targets including actinomyosin. In the mouse embryo, ROCK signaling acts to promote formation of trophectoderm (TE) and inhibit formation of the inner cell mass (ICM) by polarizing outer cells of the embryo to inactivate Hippo signaling (Kono et al., 2014; Mihajlović and Bruce, 2016)."
|More recent papers
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More? References | Discussion Page | Journal Searches | 2019 References
Search term: Bovine Embryology | Bovine Development
|These papers originally appeared in the Some Recent Findings table, but as that list grew in length have now been shuffled down to this collapsible table.
See also the Discussion Page for other references listed by year and References on this current page.
- MicroRNA Expression during Bovine Oocyte Maturation and Fertilization "In order to further explore the roles of miRNAs in oocyte maturation, we employed small RNA sequencing as a screening tool to identify and characterize miRNA populations present in pools of bovine germinal vesicle (GV) oocytes, metaphase II (MII) oocytes, and presumptive zygotes (PZ). Each stage contained a defined miRNA population, some of which showed stable expression while others showed progressive changes between stages that were subsequently confirmed by quantitative reverse transcription polymerase chain reaction (RT-PCR). Bta-miR-155, bta-miR-222, bta-miR-21, bta-let-7d, bta-let-7i, and bta-miR-190a were among the statistically significant differentially expressed miRNAs (p < 0.05). To determine whether changes in specific primary miRNA (pri-miRNA) transcripts were responsible for the observed miRNA changes, we evaluated pri-miR-155, -222 and let-7d expression. Pri-miR-155 and -222 were not detected in GV oocytes but pri-miR-155 was present in MII oocytes, indicating transcription during maturation. In contrast, levels of pri-let-7d decreased during maturation, suggesting that the observed increase in let-7d expression was likely due to processing of the primary transcript. This study demonstrates that both dynamic and stable populations of miRNAs are present in bovine oocytes and zygotes and extend previous studies supporting the importance of the small RNA landscape in the maturing bovine oocyte and early embryo." Molecular Development - microRNA
- Cell death is involved in sexual dimorphism during preimplantation development "In bovine preimplantation development, female embryos progress at lower rates and originate smaller blastocysts than male counterparts. ...Using sex-sorted semen from three different bulls for fertilization, we compared kinetics of bovine sex-specific embryos in six time points, and cell death was assessed in viable embryos. For kinetics analysis, we detected an increased population of female embryos arrested at 48 and 120h.p.i., suggesting this time points as delicate stages of development for female embryos that should be considered for testing improvement strategies for assisted reproductive technologies. Assessing viable embryos quality, we found 144h.p.i. is the first time point when viable embryos are phenotypically distinct: cell number is decreased, and apoptosis and cell fragmentation are increased in female embryos at this stage. These new results lead us to propose that sex dimorphism in viable embryos is established during morula-blastocyst transition, and cell death is involved in this process."
- Genome-Wide DNA Methylation Patterns of Bovine Blastocysts Developed In Vivo from Embryos Completed Different Stages of Development In Vitro "Early embryonic loss and altered gene expression in in vitro produced blastocysts are believed to be partly caused by aberrant DNA methylation. However, specific embryonic stage which is sensitive to in vitro culture conditions to alter the DNA methylation profile of the resulting blastocysts remained unclear. Therefore, the aim of this study was to investigate the stage specific effect of in vitro culture environment on the DNA methylation response of the resulting blastocysts. ...Therefore, this finding indicated that suboptimal culture condition during preimplantation embryo development induced changes in the DNA methylation landscape of the resulting blastocysts in a stage dependent manner and the altered DNA methylation pattern was only partly explained the observed aberrant gene expression patterns of the blastocysts."
- Influence of Sex on Basal and Dickkopf-1 Regulated Gene Expression in the Bovine morula "Sex affects function of the developing mammalian embryo as early as the preimplantation period. ...There was no effect of DKK1 on expression of any of the three genes. In conclusion, female and male bovine embryos have a different pattern of gene expression as early as the morula stage, and this is due to a large extent to expression of genes in the X chromosomes in females. Differential gene expression between female and male embryos is likely the basis for increased resistance to cell death signals in female embryos and disparity in responses of female and male embryos to changes in the maternal environment."
- Cattle Embryos from Hatched Blastocyst to Early gastrulation Stages "A detailed morphological staging system for cattle embryos at stages following blastocyst hatching and preceding gastrulation is presented here together with spatiotemporal mapping of gene expression for BMP4, BRACHYURY, CERBERUS1 (CER1), CRIPTO, EOMESODERMIN, FURIN and NODAL. Five stages are defined based on distinct developmental events."
- Expression of pluripotency master regulators during two key developmental transitions: EGA and early lineage specification in the bovine embryo "Pluripotency genes are implicated in mouse embryonic genome activation (EGA) and pluripotent lineage specification. ...Our findings affirm: firstly, the core triad of pluripotency genes is probably not implicated in bovine EGA since their proteins were not detected during pre-EGA phase, despite the transcripts for OCT4 and SOX2 were present. Secondly, an earlier ICM specification of transcripts and proteins of SOX2 and NANOG makes them pertinent candidates of bovine pluripotent lineage specification than OCT4."
- Vascular changes in the corpus luteum during early pregnancy in the cow "The present study determined vascular changes in the bovine corpus luteum (CL) at Day 16 (early maternal recognition period) and Day 40 in early pregnancy and compared them to the CL from Day 12 and Day 16 of the estrous cycle. ...The results suggest that there is no difference in vascular structure between non-pregnant and pregnant luteal tissue during the early maternal recognition period (Day 16)."
- Genome-wide expression profiling reveals distinct clusters of transcriptional regulation during bovine preimplantation development in vivo "Bovine embryos can be generated by in vitro fertilization or somatic nuclear transfer; however, these differ from their in vivo counterparts in many aspects and exhibit a higher proportion of developmental abnormalities. Here, we determined for the first time the transcriptomes of bovine metaphase II oocytes and all stages of preimplantation embryos developing in vivo up to the blastocyst using the Affymetrix GeneChip Bovine Genome Array which examines approximately 23,000 transcripts."
Genbank common name: cow, bovine, domestic cattle
Taxonomy Id: 9913 Rank: species
Genetic code: Translation table 1 (Standard)
Mitochondrial genetic code: Translation table 2 (Vertebrate Mitochondrial)
Lineage( abbreviated ): Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia; Eutheria; Laurasiatheria; Cetartiodactyla; Ruminantia; Pecora; Bovidae; Bovinae; Bos; Bos taurus
Following implantation the conceptus secretes Interferon tau (IFNT) that is the signal for maternal recognition of pregnancy (Day 16). This maintains progesterone (P4) secretion and antagonizes the endometrial cells response to phorbol 12,13-dibutyrate (PDBU) an activator of protein kinase C.
The table below shows the general timing of early development stages in the bovine embryo, as well as comparing this to other domestic species.
Implantation in the uterus occurs between 30-35 days.
|Length of Gestation
(Data: Oklahoma State University Learning Reproduction in Farm Animals)
|Cattle Gestation Periods
A historic general descriptive overview.
- First month (28 days) - The embryonic period, the embryo is 9 to 10 mm long and the first signs of extremities appear.
- Second month (30 to 60 days) - The extremities develop. The pharyngeal cleft closes in the beginning of this month. The sternum still has a longitudinal fissure in the middle, closing toward the end of the eighth week. At the end of the second month at the end of each extremity are a little conical elevation, which is colorless and transparent. This is the first indication of the hoof. The length of the fetus is 48 mm In the ninth week its length is 8 cm.
- Third month (60 to 90 days) - Toward the end of this month the four stomachs may be recognized. The fetus measures 14 cm. in length. The scrotum is present.
- Fourth month (90 to 120 days) - In the beginning of the fourth month the hoofs become quite, distinct ; they are firm, non-transparent, and have a yellow color. The fetus is about 24 cm. long and weighs up to 2 kg. (Frauck).
- Fifth month (120 to 150 days) - In the beginning of the month the first tentaculse (tactile hairs) appear on the lips, chin, upper eyelid, and orbital arch. The teats are plainly visible. The testicles descend into the scrotum. The fetus, is about 35 cm. long and weighs 2.5 to 3 kg.
- Sixth month (150 to 180 days) - The eyelashes are more developed. The foetus is about 46 cm. long. The whole body is still naked excepting the lips and eyelids.
- Seventh month (180 to 210 days) - At the end of this month a few long hairs appear at the end of the tail; also hairs about the coronet and on the spots where the horns appear. The foetus is about 60 cm. long.
- Eighth month (210 to 240 days) - The back begins to be covered with hair, also along the edges of the ears. The length of the fetus toward the 32d week is 65 cm, and toward the end of this month 75 cm. (Franck).
- Ninth month - In the beginning the whole body is covered with hair and increases greatly in size. The fetus measures from 80 to 100 cm.
- Tenth month - beginning this month the fetus becomes mature.
Bovine Estrous Cycle
Specific hormone concentrations are not shown in the above graph, only the relative hormone levels at different times during the cycle.
- Links: Estrous Cycle
Bovine ovarian follicle BMP15 and GDF9 expression
Morula and Blastocyst
Bovine morula and blastocyst.
Bovine Morula (day 4)
Bovine Blastocyst (day 7)
Bovine stem cell marker expression
- Links: Image - Morula and Blastocyst | Morula A | Blastocyst F | Blastocyst G | Bovine Development | Morula | Blastocyst
||Fetal Circulation of a Calf
Placentation is epitheliochorial, where the maternal epithelium of the uterus comes in contact with the chorion, considered as primitive. The arrows indicate the direction in which the blood flows.
A, Heart; B, umbilical opening; C, portion of the chorion. 1, Anterior aorta; 2, posterior aorta; 3 anterior vena cava; 4, posterior vena cava; 5, duct of Botalli; part of Botalli's duct posterior to the heart (sketched somewhat too long, but was necessary in order to demonstrate it) ; 6, umbilical arteries; 7, umbilical vein; 7', some of its branches; 8, portal vein; 9, ductus venosus; 10, portal veins: 11, pulmonary artery; 11', some of its branches; 12, pulmonary veins; 13, tuberculum Loweri; 14, chorion papillae.
Figure: DeBruin Bovine Obstetrics (1910)
- Links: Placenta Development
The male bovine (bull) first development of the testis at the genital ridge is triggered by SRY expression following the timeline shown below.
- Day 32 - (CRL 12) Genital ridges first appeared
- Day 37 - (CRL 18) SRY expression begins
- Day 39 - (CRL 20) SRY expression peaks
- Day 42 - (CRL 27) Testis cords distinguishable
- Links: Testis Development
- Links: Ovary Development
|Ovarian Development Model
- A - The development of the ovary commences at the mesonephric surface epithelium (yellow cells) in the location of the future gonadal ridge.
- B - Some mesonephric surface epithelial cells change phenotype into GREL (Gonadal Ridge Epithelial-Like) cells (yellow-blue cells).
- C - The GREL cells proliferate and the basal lamina underlying the mesonephric surface epithelium breaks down allowing stromal cells (green) to penetrate into the gonadal ridge.
- D - GREL cells continue to proliferate and PGCs (grey) migrate into the ridge between the GREL cells. Mesonephric stroma including vasculature (red) continues to penetrate and expand in the ovary.
- E - Oogonia proliferate and stroma penetrates further towards the ovarian surface enclosing oogonia and GREL cells into ovigerous cords. The cords are surrounded by a basal lamina at their interface with stroma, but are open to the ovarian surface. Stromal areas including those between the ovigerous cords contain capillaries.
- F - A compartmentalization into cortex and medulla becomes obvious. The cortex is characterised by alternating areas of ovigerous cords and stroma, whereas the medulla is formed by stromal cells, vasculature and tubules originating from the mesonephros (rete ovarii). Once stroma penetrates below the cells on the surface it spreads laterally. The GREL cells at the surface are then aligned by a basal lamina at their interface with the stroma and begin to differentiate into typical ovarian surface epithelium (yellow cells). Some germ cells at the surface are also compartmentalized to the surface as stroma expands below it.
- G - Ovigerous cords are partitioned into smaller cords and eventually into follicles. These contain GREL cells that form granulosa cells (blue cells) and oogonia that form oocytes. The first primordial follicles appear in the inner cortex-medulla region, surrounded by a basal lamina. A now fully intact basal lamina underlies multiple layers of surface epithelial cells.
- H - At the final stage the surface epithelium becomes mostly single-layered and a tunica albuginea, densely packed with fibres, develops from the stroma below the surface epithelial basal lamina. Some primordial follicles become activated and commence development into primary and preantral follicles.
- ↑ 1.0 1.1 van Leeuwen J, Berg DK & Pfeffer PL. (2015). Morphological and Gene Expression Changes in Cattle Embryos from Hatched Blastocyst to Early Gastrulation Stages after Transfer of In Vitro Produced Embryos. PLoS ONE , 10, e0129787. PMID: 26076128 DOI.
- ↑ 2.0 2.1 2.2 Khan DR, Dubé D, Gall L, Peynot N, Ruffini S, Laffont L, Le Bourhis D, Degrelle S, Jouneau A & Duranthon V. (2012). Expression of pluripotency master regulators during two key developmental transitions: EGA and early lineage specification in the bovine embryo. PLoS ONE , 7, e34110. PMID: 22479535 DOI.
- ↑ Krog CH, Agerholm JS & Nielsen SS. (2018). Fetal age assessment for Holstein cattle. PLoS ONE , 13, e0207682. PMID: 30452469 DOI.
- ↑ Negrón-Pérez VM, Rodrigues LT, Mingoti GZ & Hansen PJ. (2018). Role of ROCK Signaling in Formation of the Trophectoderm of the Bovine Preimplantation Embryo. Mol. Reprod. Dev. , , . PMID: 29542836 DOI.
- ↑ Gilchrist GC, Tscherner A, Nalpathamkalam T, Merico D & LaMarre J. (2016). MicroRNA Expression during Bovine Oocyte Maturation and Fertilization. Int J Mol Sci , 17, 396. PMID: 26999121 DOI.
- ↑ Oliveira CS, Saraiva NZ, de Lima MR, Oliveira LZ, Serapião RV, Garcia JM, Borges CA & Camargo LS. (2016). Cell death is involved in sexual dimorphism during preimplantation development. Mech. Dev. , 139, 42-50. PMID: 26752320 DOI.
- ↑ Salilew-Wondim D, Fournier E, Hoelker M, Saeed-Zidane M, Tholen E, Looft C, Neuhoff C, Besenfelder U, Havlicek V, Rings F, Gagné D, Sirard MA, Robert C, Shojaei Saadi HA, Gad A, Schellander K & Tesfaye D. (2015). Genome-Wide DNA Methylation Patterns of Bovine Blastocysts Developed In Vivo from Embryos Completed Different Stages of Development In Vitro. PLoS ONE , 10, e0140467. PMID: 26536655 DOI.
- ↑ Denicol AC, Leão BC, Dobbs KB, Mingoti GZ & Hansen PJ. (2015). Influence of Sex on Basal and Dickkopf-1 Regulated Gene Expression in the Bovine Morula. PLoS ONE , 10, e0133587. PMID: 26196299 DOI.
- ↑ Beindorff N, Nagai K, Shirasuna K, Herzog K, Hoeffmann K, Sasaki M, Bollwein H & Miyamoto A. (2010). Vascular changes in the corpus luteum during early pregnancy in the cow. J. Reprod. Dev. , 56, 263-70. PMID: 20103987
- ↑ Kues WA, Sudheer S, Herrmann D, Carnwath JW, Havlicek V, Besenfelder U, Lehrach H, Adjaye J & Niemann H. (2008). Genome-wide expression profiling reveals distinct clusters of transcriptional regulation during bovine preimplantation development in vivo. Proc. Natl. Acad. Sci. U.S.A. , 105, 19768-73. PMID: 19064908 DOI.
- ↑ Bruin, M. G. de. Bovine obstetrics (1910) translated by W. E. A. Wyman
- ↑ Hosoe M, Kaneyama K, Ushizawa K, Hayashi KG & Takahashi T. (2011). Quantitative analysis of bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9) gene expression in calf and adult bovine ovaries. Reprod. Biol. Endocrinol. , 9, 33. PMID: 21401961 DOI.
- ↑ 13.0 13.1 13.2 Leidenfrost S, Boelhauve M, Reichenbach M, Güngör T, Reichenbach HD, Sinowatz F, Wolf E & Habermann FA. (2011). Cell arrest and cell death in mammalian preimplantation development: lessons from the bovine model. PLoS ONE , 6, e22121. PMID: 21811561 DOI.
- ↑ Ross DG, Bowles J, Hope M, Lehnert S & Koopman P. (2009). Profiles of gonadal gene expression in the developing bovine embryo. Sex Dev , 3, 273-83. PMID: 19844082 DOI.
- ↑ Hummitzsch K, Irving-Rodgers HF, Hatzirodos N, Bonner W, Sabatier L, Reinhardt DP, Sado Y, Ninomiya Y, Wilhelm D & Rodgers RJ. (2013). A new model of development of the mammalian ovary and follicles. PLoS ONE , 8, e55578. PMID: 23409002 DOI.
Kropp J, Peñagaricano F, Salih SM & Khatib H. (2014). Invited review: Genetic contributions underlying the development of preimplantation bovine embryos. J. Dairy Sci. , 97, 1187-201. PMID: 24377798 DOI.
Aerts JM & Bols PE. (2010). Ovarian follicular dynamics: a review with emphasis on the bovine species. Part I: Folliculogenesis and pre-antral follicle development. Reprod. Domest. Anim. , 45, 171-9. PMID: 19210660 DOI.
Aerts JM & Bols PE. (2010). Ovarian follicular dynamics. A review with emphasis on the bovine species. Part II: Antral development, exogenous influence and future prospects. Reprod. Domest. Anim. , 45, 180-7. PMID: 19090819 DOI.
Gómez E, Caamaño JN, Rodríguez A, De Frutos C, Facal N & Díez C. (2006). Bovine early embryonic development and vitamin A. Reprod. Domest. Anim. , 41 Suppl 2, 63-71. PMID: 16984470 DOI.
Farin PW, Piedrahita JA & Farin CE. (2006). Errors in development of fetuses and placentas from in vitro-produced bovine embryos. Theriogenology , 65, 178-91. PMID: 16266745 DOI.
Farin CE, Farin PW & Piedrahita JA. (2004). Development of fetuses from in vitro-produced and cloned bovine embryos. J. Anim. Sci. , 82 E-Suppl, E53-62. PMID: 15471815 DOI.
O'Doherty AM, Magee DA, O'Shea LC, Forde N, Beltman ME, Mamo S & Fair T. (2015). DNA methylation dynamics at imprinted genes during bovine pre-implantation embryo development. BMC Dev. Biol. , 15, 13. PMID: 25881176 DOI.
Datta TK, Rajput SK, Wee G, Lee K, Folger JK & Smith GW. (2015). Requirement of the transcription factor USF1 in bovine oocyte and early embryonic development. Reproduction , 149, 203-12. PMID: 25385722 DOI.
Ibrahim S, Salilew-Wondim D, Rings F, Hoelker M, Neuhoff C, Tholen E, Looft C, Schellander K & Tesfaye D. (2015). Expression pattern of inflammatory response genes and their regulatory micrornas in bovine oviductal cells in response to lipopolysaccharide: implication for early embryonic development. PLoS ONE , 10, e0119388. PMID: 25764515 DOI.
Madeja ZE, Sosnowski J, Hryniewicz K, Warzych E, Pawlak P, Rozwadowska N, Plusa B & Lechniak D. (2013). Changes in sub-cellular localisation of trophoblast and inner cell mass specific transcription factors during bovine preimplantation development. BMC Dev. Biol. , 13, 32. PMID: 23941255 DOI.
Search Pubmed: bovine development
- Rauber layer - the thinned-out trophoblastic layer lying over the embryonic disk in developing carnivores and ungulates. Named after August A. Rauber (1841-1917) a German anatomist.
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