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Cite this page: Hill, M.A. (2021, December 5) Embryology Pig Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Talk:Pig_Development
Early developing pig embryos mediate their own environment in the maternal tract
PLoS One. 2012;7(3):e33625. Epub 2012 Mar 28.
Almiñana C, Heath PR, Wilkinson S, Sanchez-Osorio J, Cuello C, Parrilla I, Gil MA, Vazquez JL, Vazquez JM, Roca J, Martinez EA, Fazeli A. Source Academic Unit of Reproductive and Developmental Medicine, Department of Human Metabolism, The University of Sheffield, Sheffield, United Kingdom.
The maternal tract plays a critical role in the success of early embryonic development providing an optimal environment for establishment and maintenance of pregnancy. Preparation of this environment requires an intimate dialogue between the embryo and her mother. However, many intriguing aspects remain unknown in this unique communication system. To advance our understanding of the process by which a blastocyst is accepted by the endometrium and better address the clinical challenges of infertility and pregnancy failure, it is imperative to decipher this complex molecular dialogue. The objective of the present work is to define the local response of the maternal tract towards the embryo during the earliest stages of pregnancy. We used a novel in vivo experimental model that eliminated genetic variability and individual differences, followed by Affymetrix microarray to identify the signals involved in this embryo-maternal dialogue. Using laparoscopic insemination one oviduct of a sow was inseminated with spermatozoa and the contralateral oviduct was injected with diluent. This model allowed us to obtain samples from the oviduct and the tip of the uterine horn containing either embryos or oocytes from the same sow. Microarray analysis showed that most of the transcripts differentially expressed were down-regulated in the uterine horn in response to blastocysts when compared to oocytes. Many of the transcripts altered in response to the embryo in the uterine horn were related to the immune system. We used an in silico mathematical model to demonstrate the role of the embryo as a modulator of the immune system. This model revealed that relatively modest changes induced by the presence of the embryo could modulate the maternal immune response. These findings suggested that the presence of the embryo might regulate the immune system in the maternal tract to allow the refractory uterus to tolerate the embryo and support its development.
Temporal and spatial expression of muc1 during implantation in sows
Int J Mol Sci. 2010 May 27;11(6):2322-35.
Ren Q, Guan S, Fu J, Wang A.
College of Animal Science and Technology, China Agricultural University, Beijing 100193, China; E-Mails: firstname.lastname@example.org (Q.R.); email@example.com (S.G.). Abstract Recent evidence points to an important role for Muc1 in embryo implantation. In this study, Real-time PCR and immunohistochemistry were used to study mRNA and protein levels at, and between, the attachment sites of the endometrium of Day 13, 18 and 24 pregnant sows. The results indicate that Muc1 mRNA expression was higher between attachment sites than at attachment sites during implantation and this effect was significant on Day 13 (P < 0.01) and 24 (P < 0.01). Intense Muc1 immunostaining was observed in luminal epithelium and stroma and the staining between attachment sites was stronger than at attachment sites on Days 13 and 18. Collectively, these results suggest the crucial role of Muc1 in successful implantation and embryo survival.
- Porcine embryos begin to attach to the uterus on Days 13–14 of pregnancy
Neurulation in the pig embryo
- Neurulation in the pig embryo. van Straaten HW, Peeters MC, Hekking JW, van der Lende T. Anat Embryol (Berl). 2000 Aug;202(2):75-84. PMID: 10985427
- "Neurulation is based on a multitude of factors and processes generated both inside and outside the neural plate. Although there are models for a general neurulation mechanism, specific sets of factors and processes have been shown to be involved in neurulation depending on developmental time and rostro-caudal location at which neurulation occurred in the species under investigation. To find a common thread amongst these apparently divergent modes of neurulation another representative mammalian species, the pig, was studied here by scanning electron microscopy. The data are compared to a series of descriptions in other species. Furthermore, the relation of axial curvature and neural tube closure rate is investigated. In the pig embryo of 7 somites, the first apposition of the neural folds occurs at somite levels 5-7. This corresponds to closure site I in the mouse embryo. At the next stage the rostral and caudal parts of the rhombencephalic folds appose, leaving an opening in between. Therefore, at this stage four neuropores can be distinguished, of which the anterior and posterior ones will remain open longest. The two rhombencephalic closure sites have no counterpart in the mouse, but do have some resemblance to those of the rabbit. The anterior neuropore closes in three phases: (1) the dorsal folds slowly align and then close instantaneously, the slow progression being likely due to a counteracting effect of the mesencephalic flexure; (2) the dorso-lateral folds close in a zipper-like fashion in caudo-rostral direction; (3) the final round aperture is likely to close by circumferential growth. At the stage of 22 somites the anterior neuropore is completely closed. In contrast to the two de novo closure sites for the anterior neuropore in the mouse embryo, none of these were detected in the pig embryo. The posterior neuropore closes initially very fast in the somitic region, but this process almost stops thereafter. We suggest that the somites force the neural folds to elevate precociously. Between the stages of 8-20 somites the width of the posterior neuropore does not change, while the rate of closure gradually increases; this increase may be due to a catch-up of intrinsic neurulation processes and to the reduction of axial curvature. At the stage of 20-22 somites the posterior neuropore suddenly reduces in size but thereafter a small neuropore remains for 5 somite stages. The closure of the posterior neuropore is completed at the stage of 28 somites."
- 7 somite embryo - first apposition of the neural folds occurs at somite levels 5-7. (corresponds to closure site I in mouse).
- next stage - rostral and caudal parts of the rhombencephalic folds appose, leaving an opening in between. T
- at this stage four neuropores can be distinguished, of which the anterior and posterior ones will remain open longest. (two rhombencephalic closure sites have no counterpart in the mouse, but do have some resemblance to those of the rabbit)
- anterior neuropore closes in three phases
- dorsal folds slowly align and then close instantaneously, the slow progression being likely due to a counteracting effect of the mesencephalic flexure
- dorso-lateral folds close in a zipper-like fashion in caudo-rostral direction
- final round aperture is likely to close by circumferential growth.
22 somite embryo - anterior neuropore is completely closed. (closure sites for the anterior neuropore in mouse embryo, none of these were detected in the pig embryo)
- posterior neuropore
- closes initially very fast in the somitic region, but this process almost stops thereafter. (suggest that the somites force the neural folds to elevate precociously)
- stage 20-22 somites the posterior neuropore suddenly reduces in size but thereafter a small neuropore remains for 5 somite stages.
- closure of the posterior neuropore is completed at the stage of 28 somites.
8-20 somite embryos - the width of the posterior neuropore does not change, while the rate of closure gradually increases; this increase may be due to a catch-up of intrinsic neurulation processes and to the reduction of axial curvature. At the
EST analysis on pig mitochondria reveal novel expression differences between developmental and adult tissues
BMC Genomics. 2007 Oct 11;8:367.
Scheibye-Alsing K, Cirera S, Gilchrist MJ, Fredholm M, Gorodkin J.
Division of Genetics and Bioinformatics, IBHV, University of Copenhagen, Grønnegårdsvej 3, DK-1870 Frederiksberg, Denmark. firstname.lastname@example.org Abstract BACKGROUND: The mitochondria are involved in many basic functions in cells of vertebrates, and can be considered the power generator of the cell. Though the mitochondria have been extensively studied there appear to be only few expression studies of mitochondrial genes involving a large number of tissues and developmental stages. Here, we conduct an analysis using the PigEST resource 1 which contains expression information from 35 tissues distributed on one normalized and 97 non-normalized cDNA libraries of which 24 are from developmental stages. The mitochondrial PigEST resource contains 41,499 mitochondrial sequences.
RESULTS: The mitochondrial EST (Expressed Sequence Tag) sequences were assembled into contigs which covers more than 94 percent of the porcine mitochondrial genome, with an average of 976 EST sequences per nucleotide. This data was converted into expression values for the individual genes in each cDNA library revealing differential expression between genes expressed in cDNA libraries from developmental and adult stages. For the 13 protein coding genes (and several RNA genes), we find one set of six genes, containing all cytochrome oxidases, that are upregulated in developmental tissues, whereas the remaining set of seven genes, containing all ATPases, that are upregulated in adult muscle and brain tissues. Further, the COX I (Cytochrome oxidase subunit one) expression profile differs from that of the remaining genes, which could be explained by a tissue specific cleavage event or degradation pattern, and is especially pronounced in developmental tissues. Finally, as expected cDNA libraries from muscle tissues contain by far the largest amount (up to 20%) of expressed mitochondrial genes.
CONCLUSION: Our results present novel insight into differences in mitochondrial gene expression, emphasizing differences between adult and developmental tissues. Our work indicates that there are presently unknown mechanisms which work to customize mitochondrial processes to the specific needs of the cell, illustrated by the different patterns between adult and developmental tissues. Furthermore, our results also provide novel insight into how in-depth sequencing can provide significant information about expression patterns.
PMID: 17931413 http://www.ncbi.nlm.nih.gov/pubmed/17931413