English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The  Caenorhabditis elegans  heterochronic gene pathway, which consists of a set of regulatory genes, plays an important regulatory role in the timing of stage-specific cell lineage development in nematodes. Research into the heterochronic gene pathway gave rise to landmark microRNA (miRNA) studies and showed that these genes are important in stem cell and cancer biology; however, their functions in vertebrate development are largely unknown. To elucidate the function of the heterochronic gene pathway during vertebrate development, we cloned the zebrafish homologs of the  C. elegans let-7  miRNA-binding protein, Lin-28, and analyzed their function in zebrafish development. The zebrafish genome contains two  Lin28 -related genes,  lin-28a  and  lin-28b . Similar to mammalian Lin28 proteins, both zebrafish Lin-28a and Lin-28b have a conserved cold-shock domain and a pair of CCHC zinc finger domains, and are ubiquitously expressed during early embryonic development. In a reciprocal fashion, the expression of downstream heterochronic genes,  let-7  and  lin-4/miR-125  miRNA, occurred subsequent to  lin-28  expression. The knockdown of Lin-28a or Lin-28b function by morpholino microinjection into embryos resulted in severe cell proliferation defects during early morphogenesis. We found that the expression of  let-7  miRNA was upregulated and its downstream target gene,  lin-41 , was downregulated in these embryos. Interestingly, the expression of  miR-430 , a key regulator of maternal mRNA decay, was downregulated in  lin-28a  and  lin-28b  morphant embryos, suggesting a role for Lin-28 in the maternal-to-zygotic transition in zebrafish. Taken together, our results suggest an evolutionarily conserved and pivotal role of the heterochronic gene pathway in early vertebrate embryogenesis.

The Heterochronic Genes lin-28a and lin-28b Play an Essential and Evolutionarily Conserved Role in Early Zebrafish Development