Cellular aspects of gonadal atrophy in P-M hybrid dysgenesis

Gonadal atrophy is the most typical and dramatic manifestation of intraspecific hybrid dysgenesis syndrome leading to sterility of Drosophila melanogaster dysgenic progeny. The P-M system of hybrid dysgenesis is primarily associated with germ cell degeneration during the early stages of Drosophila development at elevated temperatures. In the present study, we have defined the phase of germ cell death as beginning at the end of embryogenesis immediately following gonad formation. The early stages of germ cell formation in dysgenic flies showed sensitivity to developmental temperature increases at any stage of the Drosophila life cycle including the imago. Analysis of germ cell reactions to hybrid dysgenesis induction revealed significant changes in subcellular structure, especially mitochondria, prior to germ cell breakdown. The mitochondrial pathology can be the reason for the activation of cell death pathways in dysgenic germ cells and lead to gonadal atrophy.

Download Full-text

Evaluation of degenerating germ cells in normal juvenile mice

Genome ◽

10.1139/g09-059 ◽

2009 ◽

Vol 52 (10) ◽

pp. 891-896 ◽

Cited By ~ 1

Author(s):

Anastassia Trifonova ◽

Peter B. Moens

Keyword(s):

Cell Death ◽

Germ Cell ◽

Germ Cells ◽

Normal Component ◽

Terminal Deoxynucleotidyl Transferase ◽

Electron Microscopic ◽

Cell Degeneration ◽

Novel Approach ◽

Two Generations ◽

Germ Cell Degeneration

Absence of spermiogenesis in mice with meiotic defects complicates the staging of meiotic arrest using light microscopy. Consequently, new methodologies are required to establish accurate relationships among germ cells. In this study, we utilized a novel approach to analyze germ cell degeneration in juvenile mice. We used terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) in combination with meiosis-specific antibodies. Germ cell degeneration is a normal component of early spermatogenesis in juvenile mice. The incidence of germ cell death was monitored at various postnatal ages of mice using the TUNEL assay to quantify the incidence of apoptosis. Cell death occurred predominantly at 15.5 days after birth. It was found that groups of apoptotic cells were apparent in tubules containing two generations of spermatocytes that form in two progressive cohorts. Electron microscopic observations further illustrated that the majority of cells in the first cohort are in late pachytene, while groups of cells in the second cohort can degenerate in early pachytene. The methodology utilized in this study is significant because it allows one to accurately determine the point at which germ cells arrest. Consequently, we believe that these methods can be applied to study animals with meiotic defects that prevent spermiogenesis.

Download Full-text

Microinjection Method for Analyzing Zebrafish Early Stage Oocytes

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.753642 ◽

2021 ◽

Vol 9 ◽

Author(s):

Manami Kobayashi ◽

Allison Jamieson-Lucy ◽

Mary C. Mullins

Keyword(s):

Functional Analysis ◽

Embryonic Development ◽

Subcellular Localization ◽

Germ Cell ◽

Analytical Methods ◽

Early Stage ◽

Cell Formation ◽

Maternal Factors ◽

Early Stages ◽

Germ Cell Formation

Maternal factors which accumulate and establish oocyte polarity during the early stages of oogenesis play key roles in embryonic development, as well as germ cell formation. However, vertebrate oogenesis, especially early stages of oogenesis, is not well understood due to the difficulty of accessing these oocytes and the lack of analytical methods. Here, we report on a microinjection method for analyzing zebrafish early-stage oocytes and some artifacts to be aware of when performing oocyte injections or analyzing oocytes. Using this method, we successfully injected mRNAs encoding fluorescent-tagged proteins into early-stage oocytes and observed subcellular localization in the live oocytes. This method is expected to advance the functional analysis of genes involved in oogenesis.

Download Full-text