Mouse Y-Encoded Transcription Factor Zfy2 Is Essential for Sperm Head Remodelling and Sperm Tail Development

Abstract

A previous study indicated that genetic information encoded on the mouse Y chromosome short arm (Yp) is required for efficient completion of the second meiotic division (that generates haploid round spermatids), restructuring of the sperm head, and development of the sperm tail. Using mouse models lacking a Y chromosome but with varying Yp gene complements provided by Yp chromosomal derivatives or transgenes, we recently identified the Y-encoded zinc finger transcription factors Zfy1 and Zfy2 as the Yp genes promoting the second meiotic division. Using the same mouse models we here show that Zfy2 (but not Zfy1) contributes to the restructuring of the sperm head and is required for the development of the sperm tail. The preferential involvement of Zfy2 is consistent with the presence of an additional strong spermatid-specific promotor that has been acquired by this gene. This is further supported by the fact that promotion of sperm morphogenesis is also seen in one of the two markedly Yp gene deficient models in which a Yp deletion has created a Zfy2/1 fusion gene that is driven by the strong Zfy2 spermatid-specific promotor, but encodes a protein almost identical to that encoded by Zfy1. Our results point to there being further genetic information on Yp that also has a role in restructuring the sperm head.

Sex and suicide: The curious case of Toll-like receptors

“…One of the most generally accepted hypotheses is that the cytoplasmic continuity they provide equalises the genomic contents of postmeiotic cells [7], thus rendering postmeiotic cells phenotypically diploid [8]. Support for this hypothesis comes from the observation that, in postmeiotic cells, X-encoded transcripts pass through intercellular bridges in the form of protein-messenger RNA (mRNA) complexes [9] and that, in general, both the X and Y chromosomes encode postmeiotically expressed genes that are essential for sperm cytodifferentiation and function, e.g., [10][11][12]. Consequently, it is undeniable that postmeiotic equalisation of X-and Y-encoded gene products across the syncytium must be essential for fertility in mammals.…”

The RNAi vecter construction and verification of the functions in sexual control of Cervus elaphus Zfx gene

“…Some studies have shown that reducing the level of Zfx/Zfy mRNA expression will make the physiological function of X/Y sperm worse, which can influence offspring gender [14,17,[20][21][22]. Zfy is closely related to sperm head and tail formation and neck development [23], which is highly expressed between meiosis I and II. It can regulate sperm morphology and ROSI efficiency, and promotes second meiosis [24,25].…”

A primer on the use of mouse models for identifying direct sex chromosome effects that cause sex differences in non-gonadal tissues

“…Specific Y genes have been identified that control specific aspects of spermatogenesis [73, 102, 104, 108, 109], but to date, no specific X gene has been identified that causes a sex chromosome effect. Because of the advent of more efficient gene targeting methods, we expect this situation to change soon.…”

“…The first cross involves a commercially available Sxr a mutation that involves translocation of Y short arm (Yp) genes to the tip of the X or Y PAR and will establish if the SCE involves Yp genes that map to Sxr a [104]. If this is not the case, the second cross utilizing a Y deletion (Y d1 ) should provide confirmation that multi-copy NPY genes are involved.…”