The patterns of sperm formation in sternorrhynchous jumping plant-lice are reviewed. To date information is available for 143 species belonging to 54 genera, 17 subfamilies and seven of the eight psylloid families (only Phacopteronidae is not represented). For the majority of the taxa (116 species, 39 genera, 10 subfamilies and the families Calophyidae, Carsidaridae and Liviidae) the data presented here is new and is based exclusively on studies using light microscopy. Five distinct patterns of chromatin reorganisation during metamorphosis of spermatids into spermatozoa are recognised, described and named here types I-V. Types I and III were previously known, types II, IV and V are described here for the first time for jumping plant-lice. The most widespread is type I which is found in every family representing the plesiomorphic condition of spermiogenesis in Psylloidea. Types III and V are autapomorphic for the Aphalarinae and Spondyliaspidinae, respectively. Type IV was found only in two genera of Euphyllurinae and may represent a synapomorphy. Type II occurs in several unrelated subfamilies and is interpreted as a homoplasy. The patterns of sperm formation are stable within most of the examined subfamilies and can be used, to a certain extent, to elucidate phylogenetic relationships within Psylloidea.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.3409/fb62_4.321 | DOI Listing |
Glucose-6-Phosphatase (G6Pase), a key enzyme in gluconeogenesis and glycogenolysis in the mammalian liver and kidney, converts glucose-6-phosphate to glucose for maintaining systemic blood glucose homeostasis during nutrient deprivation. However, its function has remained elusive in insects, which have no need for G6Pase in sugar homeostasis since they convert glucose-6-phosphate to trehalose, their main circulating sugar, via trehalose phosphate synthase (TPS1). In this study we identify an unexpected and essential requirement for G6Pase in male fertility, specifically to produce motile sperm.
View Article and Find Full Text PDFNat Rev Urol
January 2025
Discipline of Biological Sciences, College of Engineering, Science and Environment, The University of Newcastle, Callaghan, New South Wales, Australia.
Multiple conditions can cause hypoxia in the testis, including exposure to high altitude, sleep apnoea, testicular torsion and varicocele. Varicocele accounts for up to 44% of instances of primary infertility, but the cumulative contribution of hypoxic conditions to male infertility is undefined. Results of controlled hypobaric hypoxia studies have demonstrated a substantial detrimental effect of short-term and long-term exposures on sperm; however, downstream effects on embryo development and offspring health are less well understood.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
HHMI, University of California, Davis, CA 95616.
During meiosis, each pair of homologous chromosomes becomes connected by at least one crossover, as required for accurate segregation, and adjacent crossovers are widely separated thereby limiting total numbers. In coarsening models, this crossover patterning results from nascent recombination sites competing to accrue a limiting pro-crossover RING-domain protein (COR) that diffuses between synapsed chromosomes. Here, we delineate the localization dynamics of three mammalian CORs in the mouse and determine their interdependencies.
View Article and Find Full Text PDFAnn Med
December 2025
Clinical Research Center for Reproduction and Genetics in Hunan Province, Reproductive & Genetic Hospital of International Trust and Investment Corporation (CITIC)-Xiangya, Changsha, China.
Objectives: At present, most genetic tests or carrier screening are performed with blood samples, and the known carrier rate of disease-causing variants is also derived from blood. For semen donors, what is really passed on to offspring is the pathogenic variant in their sperm. This study aimed to determine whether pathogenic variants identified in the sperm of young semen donors are also present in their blood, and whether matching results for blood are consistent with results for sperm.
View Article and Find Full Text PDFZool Res
January 2025
Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, Guangdong 510623, China. E-mail:
The proteasome, an evolutionarily conserved proteolytic complex comprising the 20S core particle and 19S regulatory particles, performs both shared and distinct functions across various tissues and organs. Spermatogenesis, a highly complex developmental process, relies on proteasome activity at multiple stages to regulate protein turnover. In this study, we selected the 20S subunit PSMA1 and 19S regulatory subunit PSMD2 to investigate the potential functions of the proteasome in spermatogenesis.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!