Pgc suppresses the zygotically acting RNA decay pathway to protect germ plasm RNAs in the Drosophila embryo

TY - JOUR

T1 - Pgc suppresses the zygotically acting RNA decay pathway to protect germ plasm RNAs in the Drosophila embryo

AU - Hanyu-Nakamura, Kazuko

AU - Matsuda, Kazuki

AU - Cohen, Stephen M.

AU - Nakamura, Akira

PY - 2019/4/1

Y1 - 2019/4/1

N2 - Specification of germ cells is pivotal to ensure continuation of animal species. In many animal embryos, germ cell specification depends on maternally supplied determinants in the germ plasm. Drosophila polar granule component (pgc) mRNA is a component of the germ plasm. pgc encodes a small protein that is transiently expressed in newly formed pole cells, the germline progenitors, where it globally represses mRNA transcription. pgc is also required for pole cell survival, but the mechanism linking transcriptional repression to pole cell survival remains elusive. We report that pole cells lacking pgc show premature loss of germ plasm mRNAs, including the germ cell survival factor nanos, and undergo apoptosis. We found that pgc- pole cells misexpress multiple miRNA genes. Reduction of miRNA pathway activity in pgc- embryos partially suppressed germ plasm mRNA degradation and pole cell death, suggesting that Pgc represses zygotic miRNA transcription in pole cells to protect germ plasm mRNAs. Interestingly, germ plasm mRNAs are protected from miRNA-mediated degradation in vertebrates, albeit by a different mechanism. Thus, independently evolved mechanisms are used to silence miRNAs during germ cell specification.

AB - Specification of germ cells is pivotal to ensure continuation of animal species. In many animal embryos, germ cell specification depends on maternally supplied determinants in the germ plasm. Drosophila polar granule component (pgc) mRNA is a component of the germ plasm. pgc encodes a small protein that is transiently expressed in newly formed pole cells, the germline progenitors, where it globally represses mRNA transcription. pgc is also required for pole cell survival, but the mechanism linking transcriptional repression to pole cell survival remains elusive. We report that pole cells lacking pgc show premature loss of germ plasm mRNAs, including the germ cell survival factor nanos, and undergo apoptosis. We found that pgc- pole cells misexpress multiple miRNA genes. Reduction of miRNA pathway activity in pgc- embryos partially suppressed germ plasm mRNA degradation and pole cell death, suggesting that Pgc represses zygotic miRNA transcription in pole cells to protect germ plasm mRNAs. Interestingly, germ plasm mRNAs are protected from miRNA-mediated degradation in vertebrates, albeit by a different mechanism. Thus, independently evolved mechanisms are used to silence miRNAs during germ cell specification.

KW - Germ cell

KW - Germ plasm

KW - Maternal-to-zygotic transition

KW - microRNA

KW - Transcriptional repression

U2 - 10.1242/dev.167056

DO - 10.1242/dev.167056

M3 - Journal article

C2 - 30890569

AN - SCOPUS:85064286965

SN - 0950-1991

VL - 146

JO - Development

JF - Development

IS - 7

M1 - 167056

ER -