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Ovarian polarity and cell shape determination by Btk29A in Drosophila
Author(s) -
HamadaKawaguchi Noriko,
Yamamoto Daisuke
Publication year - 2017
Publication title -
genesis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.093
H-Index - 110
eISSN - 1526-968X
pISSN - 1526-954X
DOI - 10.1002/dvg.23042
Subject(s) - adherens junction , microbiology and biotechnology , biology , mutant , armadillo , polarity (international relations) , subcellular localization , phenotype , cell polarity , phosphorylation , tyrosine , cytoplasm , gene isoform , cadherin , gene , cell , genetics , biochemistry
Drosophila Btk29A is a Tec family nonreceptor tyrosine kinase, the ortholog of which causes X‐linked agammaglobulinemia in humans when mutant. In Btk29A ficP mutant ovaries, multiple defects are observed: extrapolar cells form ectopically; osk mRNA fails to accumulate posteriorly in mature oocytes; the shape and alignment of follicle cells are grossly distorted. All these phenotypes are rescued by selectively overexpressing the type 2 isoform of wild‐type Btk29A in follicle cells. Expression of certain proteins enriched in adherens junctions is markedly affected in Btk29A ficP mutants; the anterior–posterior gradient normally observed in the expression of D E‐Cadherin and Armadillo are lost and Canoe is sequestered from adherens junctions. Intriguingly, tyrosine phosphorylation of Canoe is reduced in Btk29A ficP mutants. It is proposed that Btk29A is required for the establishment of egg chamber polarity presumably through the regulation of subcellular localization of its downstream proteins, including Cno.