It is important for the proper execution of cell division in both mitosis and meiosis that the chromosome segregation, cytokinesis, and partition of cell organelles progress in smooth coordination. We show here that the mitochondria inheritance is closely linked with microtubules during meiotic divisions in Drosophila males. They are first clustered in a cell equator at metaphase associated with astral microtubules and then distributed along central spindle microtubules after anaphase. The molecular mechanism for the microtubule-dependent inheritance of mitochondria in male meiosis has not been demonstrated yet. We first isolated mutations for a larp gene that is highly conserved among eukaryotes and showed that these mutant males exhibited multiple meiotic phenotypes such as a failure of chromosome segregation, cytokinesis, and mitochondrial partition. Our cytological examination revealed that the mutants showed defects in spindle pole organization and spindle formation. The larp encodes a Drosophila orthologue of a La-related protein containing a domain exhibiting an outstanding homology with a La type RNA-binding protein. Surprisingly, the dLarp protein is localized in the cytoplasm of the male germ line cells, as observed by its distinct co-localization with mitochondria in early spermatocytes and during meiotic divisions. We discuss here the essential role that dLarp plays in multiple processes in Drosophila male meiosis.
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http://dx.doi.org/10.1247/csf.07027 | DOI Listing |
Biol Reprod
January 2025
Department of Anatomy and Cell Biology, Brody School of Medicine, East Carolina University, Greenville, NC USA.
The adult mammalian testis is filled with seminiferous tubules, which contain somatic Sertoli cells along with germ cells undergoing all phases of spermatogenesis. During spermatogenesis in postnatal mice, male germ cells undergo at least 17 different nomenclature changes as they proceed through mitosis as spermatogonia (=8), meiosis as spermatocytes (=6), and spermiogenesis as spermatids (=3) [1-6]. Adding to this complexity, combinations of germ cells at each of these stages of development are clumped together along the length of the seminiferous tubules.
View Article and Find Full Text PDFDev Cell
January 2025
Department of Biological Sciences and Temasek Life Sciences Laboratory, National University of Singapore, Singapore 117543, Singapore. Electronic address:
N-methyladenosine (mA) RNA modification and its effectors control various plant developmental processes, yet whether and how these effectors are transcriptionally controlled to confer functional specificity so far remain elusive. Herein, we show that a rice C2H2 zinc-finger protein, OsZAF, specifically activates the expression of OsFIP37 encoding a core component of the mA methyltransferase complex during microsporogenesis in rice anthers. OsFIP37, in turn, facilitates mA modification and stabilization of an auxin biosynthesis gene OsYUCCA3 to promote auxin biosynthesis in anthers.
View Article and Find Full Text PDFBMC Genomics
January 2025
Department of Animal Sciences, Purdue University, 270 S. Russell Street, West Lafayette, IN, 47907, USA.
Background: The profitability of the beef industry is directly influenced by the fertility rate and reproductive performance of both males and females, which can be improved through selective breeding. When performing genomic analyses, genetic markers located on the X chromosome have been commonly ignored despite the X chromosome being one of the largest chromosomes in the cattle genome. Therefore, the primary objectives of this study were to: (1) estimate variance components and genetic parameters for eighteen male and five female fertility and reproductive traits in Nellore cattle including X chromosome markers in the analyses; and (2) perform genome-wide association studies and functional genomic analyses to better understand the genetic background of male and female fertility and reproductive performance traits in Nellore cattle.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Cell Biology, Duke University Medical Center, Durham, NC 27701.
In species with genetic sex determination (GSD), the sex identity of the soma determines germ cell fate. For example, in mice, XY germ cells that enter an ovary differentiate as oogonia, whereas XX germ cells that enter a testis initiate differentiation as spermatogonia. However, numerous species lack a GSD system and instead display temperature-dependent sex determination (TSD).
View Article and Find Full Text PDFGigascience
January 2025
Centre for Evolutionary & Organismal Biology, Zhejiang University School of Medicine, Hangzhou 310058, China.
Background: A thorough analysis of genome evolution is fundamental for biodiversity understanding. The iconic monotremes (platypus and echidna) feature extraordinary biology. However, they also exhibit rearrangements in several chromosomes, especially in the sex chromosome chain.
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