Talk:Pig Development

2010

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: qianer0101@gmail.com (Q.R.); guanshu8@gmail.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

PMID: 20640155

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2904919/?tool=pubmed

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

1. dorsal folds slowly align and then close instantaneously, the slow progression being likely due to a counteracting effect of the mesencephalic flexure
2. dorso-lateral folds close in a zipper-like fashion in caudo-rostral direction
3. 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