Overexpression of <i>Lis1</i> in Different Stages of Spermatogenesis Does Not Result in an Aberrant Phenotype

Abstract

Previous studies showed that in the mouse mutant Lis1^GT/GT gene trap integration in intron 2 of Lis1 gene leads to male infertility in homozygous Lis1^GT/GT mice. We further analyzed this line and could confirm the suggested downregulation of a testis-specific Lis1 transcript in mutant animals in a quantitative manner. Moreover, we analyzed the gene trap mutation on different genetic backgrounds in incipient congenic animals and could exclude a genetic background effect. To gain further insights into the role and requirement of LIS1 in spermatogenesis, 3 transgenic lines were generated, that overexpress Lis1 under control of the testis-specific promoters hEF-1α, which is exclusively active in spermatogonial cells, PGK2, which is active in pachytene spermatocytes and following stages of spermatogenesis, and Tnp2 which is active in round spermatids and following stages of spermatogenesis, respectively. All 3 transgenic lines remained fertile and testis sections displayed no abnormalities. To overcome the infertility of Lis1^GT/GT males, these transgenic Lis1-overexpressing animals were mated with Lis1^GT/GT mice to generate ‘rescued’ Lis1^GT/GT/Lis1^Tpos males. ‘Rescued’ animals from all transgenic lines remained infertile, thus overexpression of Lis1 in different stages of spermatogenesis could not rescue the infertility phenotype of homozygous gene trap males.

Analysis of circRNA-miRNA-mRNA regulatory network of embryonic gonadal development in Mulard duck

“…Male mice with mutations in both the alpha1 and alpha2 subunits were infertile due to severe spermatogenesis impairment ( Koizumi et al, 2003 ). To determine whether the fertility of double-subunit knockout mice can be restored, the overexpression of PAFAH1B1 had no significant effect on spermatogenesis, different promoters regulating PAFAH1B1 expression can affect each stage of spermatogenesis, and the use of the 5′-UTR and 3′-UTR in transgenesis may rescue genetic sterility defects ( Drusenheimer et al, 2011 ). While PAFAH1B1 levels are reduced by inactivating PAFAH1B1 alleles, the spermatogenesis and fertility of male mice with alpha1 and alpha2 subunit mutations could be restored ( Yan et al, 2003 ).…”

Role of PAFAH1B1 in human spermatogenesis, fertilization and early embryonic development

“…Expression analysis in mice revealed that PAFAH1B1 mRNA is expressed in almost all cell types studied, although certain splicing and polyadenylation variants are differentially found in adult brain, heart and testis. For instance, an additional 2α exon was identified in the 5′ UTR of the transcript expressed in testis (Drusenheimer et al, 2011;Nayernia et al, 2003), although this has not been investigated for the human transcript. In fact, PAFAH1B1 is abundantly expressed in the male gonad and, in particular, within dividing spermatocytes and elongating spermatids (Drusenheimer et al, 2011;Koizumi et al, 2003).…”

“…For instance, an additional 2α exon was identified in the 5′ UTR of the transcript expressed in testis (Drusenheimer et al, 2011;Nayernia et al, 2003), although this has not been investigated for the human transcript. In fact, PAFAH1B1 is abundantly expressed in the male gonad and, in particular, within dividing spermatocytes and elongating spermatids (Drusenheimer et al, 2011;Koizumi et al, 2003). Regarding its function in testis, germcell specific overexpression of PAFAH1B1 had no influence on spermatogenesis (Drusenheimer et al, 2011).…”

“…In fact, PAFAH1B1 is abundantly expressed in the male gonad and, in particular, within dividing spermatocytes and elongating spermatids (Drusenheimer et al, 2011;Koizumi et al, 2003). Regarding its function in testis, germcell specific overexpression of PAFAH1B1 had no influence on spermatogenesis (Drusenheimer et al, 2011). Conversely, heterozygous PAFAH1B1 +/transgenic males, although still fertile, displayed a reduction in testis weight and seminiferous tubule diameter, with the presence of degenerating germ cells (Yan et al, 2003).…”

“…So far, studies of the roles of PAFAH1B1 in male and female reproduction are limited to mice (Cahana and Reiner, 1999;Cahana et al, 2003;Drusenheimer et al, 2011;Koizumi et al, 2003;Nayernia et al, 2003;Yan et al, 2003), rhesus monkeys, cattle (Payne et al, 2003), Drosophila (Liu et al, 1999;Sitaram et al, 2012) and C. elegans (Cockell et al, 2004). Because little is known about the role of PAFAH1B1 in human reproductive function, in this study its expression pattern in testicular tissue and spermatozoa from men with different spermatogenic abilities was investigated, as well as in oocytes and embryos.…”