The development of female germ cells can be mainly divided into two stages: fetal germ cells and oocytes in folliculogenesis after puberty. Mitosis-meiosis transition, meiosis arrest and re-activation are the key phases of the development. Several phases may be characterized by their distinct molecular events, which involve precise regulation of gene expression and interaction with corresponding gonadal niche cells. In recent years, single-cell transcriptome studies have clarified phase-specific patterns of gene expression, signaling pathways and epigenetic modification during oogenesis and folliculogenesis. These works have provided important insights into the development of female germ cells and pathogenesis of germ-cell related diseases, which may promote clinical application of reproductive genetic research.
Female ; Germ Cells ; Humans ; Meiosis ; Oocytes ; Oogenesis/genetics* ; Signal Transduction

Apomixis has been widely concerned because of its great potential in heterosis fixation. Artificial apomixis is an important direction of current apomixis research. Mitosis instead of Meiosis (MIME) produces diploid gametes that is identical with the maternal genetic composition and is a key step in the artificial creation of apomixes. This paper reviews the occurrence of MIME and its application in crop apomixis and the problems encountered, in an aim to provide reference for expanding the application of MIME in crop apomixis.
Apomixis ; Crops, Agricultural ; genetics ; Diploidy ; Germ Cells ; Meiosis ; Mitosis

Chromosome Banding ; Chromosome Disorders ; genetics ; Chromosomes, Human, Pair 12 ; genetics ; Humans ; Infant ; Isochromosomes ; genetics ; Male ; Meiosis

Adult ; Chromatids/genetics* ; Chromosome Aberrations ; Humans ; Infertility, Male/genetics* ; Male ; Meiosis ; Metaphase/genetics* ; Spermatocytes/physiology*

Chromosomal translocation is a kind of common chromosomal abnormality. The carriers with chromosomal translocation could have more chance of normal pregnancy with the help of fluorescence in situ hybridization(FISH). This is a review aimed at analyzing the meiosis types of the translocation chromosome. The strategy of preimplantation genetic diagnosis for the carriers with chromosomal translocation is also discussed.
Humans ; In Situ Hybridization, Fluorescence ; methods ; Meiosis ; genetics ; Preimplantation Diagnosis ; methods ; Translocation, Genetic ; genetics

OBJECTIVETo analyze the meiotic segregation results of male reciprocal chromosome translocation by fluorescence in situ hybridization (FISH).

METHODSMulti-color FISH using 3 combined probes located in any 3 chromosome segments on both sides of two breakpoints was performed on the de-condensed sperm head to analyze the sperm chromosomal contents and segregation patterns.

RESULTSFour male reciprocal translocation carriers were included in the study, with the karyotypes of 46, XY, t(2;18) (p16; q23); 46, XY, t(4;6) (q34;q21); 46, XY, t(8;13) (q23;q21) and 46, XY, t(4;5) (4q31;5q13), respectively. The results showed that 4 carriers had different proportions of various segregated spermatozoa. The spermatozoa of alternate, adjacent-1, adjacent-2, 3:1, non-disjunction in meiosis II, and 4:0 or diploidy accounted for 27.1%-49.4%, 26.9%-37.6%, 2.7%-15.7%, 8.6%-32.7%, 0.2%-1.9%, and 0.1%-0.4%, respectively.

CONCLUSIONFor each-reciprocal translocation carrier seems to have a particular meiotic segregation results, FISH analysis on sperm head should be done for each carrier in order to provide an accurate genetic counseling.

Chromosome Breakage ; Heterozygote ; Humans ; In Situ Hybridization, Fluorescence ; Karyotyping ; Male ; Meiosis ; genetics ; Spermatozoa ; metabolism ; Translocation, Genetic ; genetics

Primary ovarian insuffiency (POI), which accounts for female infertility, is characterized by amenorrhea before the age of 40 and high serum level of follicular stimulating hormone (>40 U/L) at two measurements taken at least one month apart. The disorder is believed to have a strong genetic component. A large number of candidate genes have been proposed, though few of them were extensively studied. With the rapid evolvement of genome sequencing technology, recent research raised the possibility that the genes involved in essential steps of meiosis such as chromosome synapsis and recombination play an important role in the pathogenesis of POI. Clarifying the genetic pathogenesis of POI not only can enhance understanding of the molecular mechanism of reproductive functions and infertility, but also provide accurate information for genetic counseling for such patients.
Female ; Follicle Stimulating Hormone ; metabolism ; Humans ; Infertility, Female ; genetics ; Meiosis ; Primary Ovarian Insufficiency ; genetics ; metabolism

Meiosis is an essential step in gametogenesis which is the key process in sexually reproducing organisms as meiotic aberrations may result in infertility. In meiosis, programmed DNA double-strand break (DSB) formation is one of the fundamental processes that are essential for maintaining homolog interactions and correcting segregation of chromosomes. Although the number and distribution of meiotic DSBs are tightly regulated, still abnormalities in DSB formation are known to cause meiotic arrest and infertility. This review is a detailed account of molecular bases of meiotic DSB formation, its evolutionary conservation, and variations in different species. We further reviewed the mutations of DSB formation genes in association with human infertility and also proposed the future directions and strategies about the study of meiotic DSB formation.
DNA Breaks, Double-Stranded ; DNA Repair/genetics* ; Humans ; Infertility/genetics* ; Meiosis/physiology*

Aurora kinase A (AURKA),a family member of aurora kinases,is involved in mitotic entry,maturation and separation of centrosome,assembly and stabilization of bipolar spindle,and condensation and separation of chromosome.Studies have demonstrated that AURKA plays a similar role in meiosis,while the specific mechanism and the similarities and differences in its role between meiosis and mitosis remain unclear.Therefore,we reviewed the studies about the localization and activation of AURKA in oocyte meiosis,and compared the role of AURKA in regulating spindle formation,activating spindle assembly checkpoint,and correcting the kinetochore-microtubule attachment between the meiosis of oocytes and the mitosis of somatic cells.This review will lay a theoretical foundation for revealing the mechanism of AURKA in the regulation of cell division and for the clinical research related to cancer and reproduction.
Aurora Kinase A/genetics* ; Cell Cycle Proteins/genetics* ; Chromosome Segregation ; Humans ; Meiosis ; Oocytes

Male infertility is a worldwide problem, and about 15% of the cases are associated with spermatogenesis-related gene mutation. The mammalian gene UBE2B is the homolog of the RAD6 gene of yeast, belonging to the ubiquitin proteasome system and playing an important role in spermatogenesis. Mice lacking the UBE2B gene are infertile, with reduced sperm motility, increased morphologically abnormal sperm, and inhibited meiosis of spermatogonia. Accumulated evidence shows that UBE2B gene mutants and single nucleotide polymorphisms are associated with male infertility. This article reviews the relation between the UBE2B gene and male infertility, offering some theoretical evidence for the diagnosis and treatment of male infertility.
Animals ; Asthenozoospermia ; genetics ; Humans ; Infertility, Male ; genetics ; Male ; Meiosis ; Mice ; Mutation ; Polymorphism, Single Nucleotide ; Spermatogenesis ; genetics ; Ubiquitin-Conjugating Enzymes ; genetics