
Casparは、ドロソフィラ胚の始原生殖細胞の同定と形成に重要な役割を果たす。Casparの欠失や過剰発現は、始原生殖細胞の数に逆相関の影響を及ぼす。


coremsg

Repurposing of pleiotropic factors during execution of diverse cellular processes has emerged as a regulatory paradigm. Embryonic development in metazoans is controlled by maternal factors deposited in the egg during oogenesis. Here, we explore maternal role(s) of Caspar (Casp), the Drosophila orthologue of human Fas-associated factor-1 (FAF1) originally implicated in host-defense as a negative regulator of NF-κB signaling. Maternal loss of either Casp or it’s protein partner, Transitional endoplasmic reticulum 94 (TER94) leads to partial embryonic lethality correlated with aberrant centrosome behavior, cytoskeletal abnormalities, and defective gastrulation. Although ubiquitously distributed, both proteins are enriched in the primordial germ cells (PGCs), and in keeping with the centrosome problems, mutant embryos display a significant reduction in the PGC count. Moreover, the total number of pole buds is directly proportional to the level of Casp. Consistently, it’s ‘loss’ and ‘gain’ results in respective reduction and increase in the Oskar protein levels, the master determinant of PGC fate. To elucidate this regulatory loop, we analyzed several known components of mid-blastula transition and identify the translational repressor Smaug, a zygotic regulator of germ cell specification, as a potential critical target. We present a detailed structure-function analysis of Casp aimed at understanding its novel involvement during PGC development.

### Competing Interest Statement

The authors have declared no competing interest.

Caspar determines primordial germ cell identity in Drosophila melanogaster

ドロソフィラ-メラノガスターにおける始原生殖細胞の同定におけるcasparの役割


ドロソフィラ・メラノガスターにおける始原生殖細胞の同定におけるCasparの役割
