The indispensable contribution of s38 protein to ovarian-eggshell morphogenesis in Drosophila melanogaster

Abstract

Drosophila chorion represents a remarkable model system for the in vivo study of complex extracellular-matrix architectures. For its organization and structure, s38 protein is considered as a component of major importance, since it is synthesized and secreted during early choriogenesis. However, there is no evidence that proves its essential, or redundant, role in chorion biogenesis. Hence, we show that targeted downregulation of s38 protein, specifically in the ovarian follicle-cell compartment, via employment of an RNAi-mediated strategy, causes generation of diverse dysmorphic phenotypes, regarding eggshell’s regionally and radially specialized structures. Downregulation of s38 protein severely impairs fly’s fertility and is unable to be compensated by the s36 homologous family member, thus unveiling s38 protein’s essential contribution to chorion’s assembly and function. Altogether, s38 acts as a key skeletal protein being critically implicated in the patterning establishment of a highly structured tripartite endochorion. Furthermore, it seems that s38 loss may sensitize choriogenesis to stochastic variation in its coordination and timing.

Post‐mating gene expression of Mexican fruit fly females: disentangling the effects of the male accessory glands

“…In addition to impacting the lipid biosynthesis pathway, mating in A. ludens also regulated transcripts with D. melanogaster orthologs involved in eggshell formation. Five mating‐regulated transcripts (AL_68575, AL_72286, AL_30126, AL_28122, AL_72596) have D. melanogaster orthologs (FBgn0014465, FBgn0000359, FBgn0000360, FBgn0004650) associated with vitelline membrane and chorion formation (Velentzas et al ., 2018). Four of the A. ludens transcripts (AL_68575, AL_72286, AL_30126, AL_28122) are down‐regulated by mating.…”

ATG3 Is Important for the Chorion Ultrastructure During Oogenesis in the Insect Vector Rhodnius prolixus

“…The process of chorion formation represents a remarkable model system for studying in vivo the biogenesis of complex extracellular matrix architectures. In Drosophila , studies about choriogenesis focus mostly on the programed gene-specific transcriptional activation of chorion genes ( Tootle et al, 2011 ; Velentzas et al, 2018 ), and on the biochemical characterization of chorion proteins by mass spectrometry ( Fakhouri et al, 2006 ). The fact that LC3-lipidation was reduced in ATG3-depleted samples indicates that the autophagic canonical function of ATG3 was indeed altered in the oocytes.…”

“…The process of chorion formation and its complex ultrastructure represent a remarkable model for in vivo studies of biogenesis and assembly of the network of macromolecules in an extracellular matrix. In Drosophila , studies about choriogenesis focus mostly on the programed gene-specific transcriptional activation of chorion genes ( Tootle et al, 2011 ; Velentzas et al, 2018 ) and on the biochemical characterization of chorion proteins, mainly by mass spectrometry ( Fakhouri et al, 2006 ). In Rhodnius prolixus , the chorion ultrastructure and permeability properties were previously explored ( Beament, 1948 ; Dias et al, 2013 ; Bomfim et al, 2017 ; Bomfim and Ramos, 2020 ) and the identification of the specific chorion proteins Rp30 and Rp45, the latter associated to an antifungal activity, were also described ( Bouts et al, 2007 ).…”

Deficiency of ULK1/ATG1 in the follicle cells disturbs ER homeostasis and causes defective chorion deposition in the vectorRhodnius prolixus

“…The process of chorion formation represents a remarkable model system for studying in vivo the biogenesis of complex extracellular matrix architectures. In Drosophila, studies about choriogenesis focus mostly on the programed gene-specific transcriptional activation of chorion genes 30,31 and on the biochemical characterization of chorion proteins, mainly by mass spectrometry. 32 Nevertheless, the machinery and signaling pathways encompassing the chorion proteins synthesis, sorting, and secretion in the FCs are still largely unexplored.…”