Lamins A and C are present in the nuclei of early porcine embryos, with lamin A being distributed in large intranuclear foci

Abstract

Gametogenesis and embryogenesis are dynamic developmental stages marked by extensive modifications in the organization of the genome and nuclear architecture. In the literature it is conveyed that only B-type lamins are required in these early stages of development and that A-type lamins are not present or required until differentiation of specific cell types associated with specialized tissue is initiated. To assess the presence of nuclear structures that are putatively involved in genome regulation, we investigated the distribution of lamin proteins throughout the early stages of porcine embryonic development, using testes tissue sections, oocytes and in-vitro fertilized (IVF) porcine embryos and employing anti-lamin antibodies. We have shown that anti-lamin A staining is present at the one-cell, two-cell, four-cell, and six- to eight-cell stages of early porcine embryo development, but diminishes at the morulae and blastocyst stages. Large intranuclear anti-lamin A foci are prominent in the early preimplantation stages. Both anti-lamin A/C and anti-lamin B staining were clearly present in all embryonic stages. Immature porcine oocytes revealed lamin rings using the monoclonal anti-lamin A/C antibody and many immature oocytes exhibited a pale rim staining pattern with anti-lamin A antibody. A-type lamins were not observed in sperm precursor cells. Thus, we have shown that A-type lamins and B-type lamins are present at the nuclear envelope in very early porcine embryos and that lamin A is also found in large intranuclear aggregates in two-cell to eight-cell embryos but is lacking from later embryonic stages.

The Role of the Nuclear Lamina in Cancer and Apoptosis

“…Strikingly, both studies showed a nucleolar rather than a nuclear lamina staining in some basal cell carcinomas using a lamin C antibody. Whether this staining corresponds to the intranuclear foci seen in early embryonal development [ 15 ] remains to be examined.…”

Do lamin A and lamin C have unique roles?

“…Foster and coworkers reported variation in lamin A expression but not lamin C during porcine embryonic development. They showed that lamin A was only found in early embryonic stages of pigs, in two-cell to eight-cell embryos, but absent from later embryonic stages (Foster et al 2007). In addition, the ratio between the A-type lamins changed during development in the nuclear fraction from the tongue muscle of rats (Sato et al 2006).…”

Embryonic Senescence and Laminopathies in a Progeroid Zebrafish Model

“…Whilst the crucial involvement of lamin A and lamina-associated polypeptide (LAP) 2α in the regulation of stem cells has been suggested previously [18] [19] [20] [21] [22] [23] [24], and several developmental studies have been performed in model animals including Drosophila , Xenopus , chicken, cow and mouse [25] [26] [27] [28] [29] [30], the essential roles for this gene and its requirement during early vertebrate development are still poorly understood in vivo . In addition, several gene perturbations identified by microarray profiling have also now been confirmed in HGPS fibroblasts [31] [32] [33] [34], but very few have been validated extensively in animal models.…”