Male infertility is a worldwide problem, with a variety of causes including genetic factors. Sex chromosomes are particularly interesting, as males only have a single copy of both chromosomes. The Y chromosome is obviously an area of interest in the study of male-factor infertility because it contains many of the genes that are critical for spermatogenesis and the development of male gonads. Y chromosome microdeletions are the most commonly known genetic causes of spermatogenic failure in males. The azoospermia factor (AZF) region is a particular area on the long arm of the Y chromosome, Yq, where microdeletions occur most frequently. Fourteen Y chromosome genes encoding putatively functional proteins and expressed in the human testis are found to be located in one of the three AZF intervals. The exact role of specific AZF genes in spermatogenesis is largely unknown, for each of the most classical Yq deletions removes multiple genes. The importance of the X chromosome in mammalian spermatogenesis is suggested by its enrichment of germ cell-specific genes expressed in spermatogenesis, such as AR, USP26, TAF7L, TEX11, KAL1, AKAP4, and NXF2. Genes on the X chromosome may be under unique evolutionary pressure due to their hemizygous expression in male. The mutations in the single copy X-linked genes, unlike in autosomal genes, would not be masked by a normal allele. Many researches have been conducted on the relationship between spermatogenesis and the genes on the X chromosome, but the involvement of the X chromosome in male infertility remains less understood and deserves further characterization.
Humans ; Infertility, Male ; genetics ; Male ; Sex Chromosomes

As a male-specific chromosome, the structure of Y chromosome is complex and lacks of recombination, with numerous repeating, amplifying and palindromic sequences. The research of Y chromosome is difficult and slow since there are few protein coding genes and a large amount of heterochromatin which has caused extreme difficulty for sequencing. In recent years, an increasing number of studies have been focused on the Y chromosome. With the completion of the sequencing of human Y chromosome, the rapid development of sequencing technology, and the composition of DNA sequences in human Y chromosomes and the determination of gene content. This paper has summarized the structural composition and genes function of human Y chromosome, as well as the related hereditary diseases, with an aim to provide reference for Y chromosome-related genetic research.
Chromosomes, Human, Y/genetics* ; Humans ; Male

Linear chromatin is compacted into eukaryotic nucleus through a complex and multi-layered architecture. Consequently, chromatin conformation in a local or long-distance manner is strongly correlated with gene expression. Chromosome conformation capture (3C) technology, together with its variants like 4C/5C/Hi-C, has been well developed to study chromatin looping and whole genome structure. In this review, we introduce new technologies including chromosome capture combined with immunoprecipitation, nuclei acid-based hybridization, single cell and genome sequencing, as well as their application.
Cell Nucleus ; Chromatin/genetics* ; Chromosomes/genetics* ; Genetic Techniques ; Genome/genetics*

OBJECTIVETo explore the genetics mechanism for the phenotypic variability in a patient carrying a rare ring chromosome 9.

METHODSThe karyotype of the patient was analyzed with cytogenetics method. Presence of sex chromosome was confirmed with fluorescence in situ hybridization. The SRY gene was subjected to PCR amplification and direct sequencing. Potential deletion and duplication were detected with array-based comparative genomic hybridization (array-CGH).

RESULTSThe karyotype of the patient has comprised 6 types of cell lines containing a ring chromosome 9. The SRY gene sequence was normal. By array-CGH, the patient has carried a hemizygous deletion at 9p24.3-p23 (174 201-9 721 761) encompassing 30 genes from Online Mendelian Inheritance in Man.

CONCLUSIONThe phenotypic variability of the 9p deletion syndrome in conjunct with ring chromosome 9 may be attributable to multiple factors including loss of chromosomal material, insufficient dosage of genes, instability of ring chromosome, and pattern of inheritance.

Chromosomes, Human, Pair 9 ; genetics ; Female ; Humans ; Infant ; Karyotype ; Male ; Ring Chromosomes ; Sex Chromosome Disorders ; genetics

Child, Preschool ; Chromosomes, Human, Pair 11 ; Female ; Humans ; Kidney Neoplasms ; genetics ; Ring Chromosomes ; Wilms Tumor ; genetics

This article aimed to report two cases of Burkitt lymphoma/leukemia with concurrent t(8;14) and t(14;18). Morphology, immunophenotype, cytogenetics and molecular biology (MICM) methods were applied to diagnosis. The results showed that the two cases were both acute lymphocytic leukemia L3 type according to FAB criteria. Conventional cytogenetic technique or interphase fluorescence in situ hybridization (FISH) demonstrated that t(8;14) and t(14;18) were detected concurrently in both patients. CD20, CD10, FMC7, CD38 and CD19 were expressed in both patients by immunophenotyping. According to MICM, they were both diagnosed as Burkitt lymphoma/leukemia. The first patient died in one month after chemotherapy, and the second patient survived 19 months after rituximab- combined high-dose chemotherapy and subsequently allogeneic hematopoietic stem cell transplantation (HSCT). In conclusion, t(8;14) and t(14;18) may present simultaneously in Burkitt lymphoma/leukemia and indicate poor prognosis. Rituximab-combined chemotherapy and subsequently HSCT could improve the outcomes of such cases.
Burkitt Lymphoma ; genetics ; Chromosomes, Human, Pair 14 ; genetics ; Chromosomes, Human, Pair 18 ; genetics ; Chromosomes, Human, Pair 8 ; genetics ; Female ; Humans ; Lymphoma ; genetics ; Male ; Middle Aged ; Translocation, Genetic

OBJECTIVETo study the karyotype of four Ephedra plants in order to provide the cytologic evidence for the genetic diversity and identification genetic resources of Ephedra.

METHODThe roots of germinating seeds were used to study the karyotype of four Ephedra plants by staining and slide-preparing technique of mitotic chromosomes.

RESULTthe optimal root-sampling time was about 10: 20 - 10:40 am. Using 0.002 mol x L(-1) 8-Hydroxyquinoline to pretreating the intravital root tips, the optimal pretreatment time for E. Sinica, E. intermedina, E. equisetina and E. przewalskii was 4, 5, 4.5 and 3.5 h, respectively. E. przewalskii and E. equisetina were diploid, E. Sinica and E. intermedina were belonged quadruple. The karyotype formulae of the four species were 2n = 2x = 14 = 2M + 8m + 4sm, 2n = 2x = 14 = 10m + 4st, 2n = 4x = 28 = 20m (2SAT) +8st, and 2n = 4x = 28 = 20m (SAT) + 6st + 2sm, respectively.

CONCLUSIONAll the karyotypes of four Ephedra species were 2A type, which was the symmetric karyotype.

Chromosomes, Plant ; genetics ; Ephedra ; cytology ; genetics ; Karyotyping ; methods ; Mitosis

In the present paper, three Coptis species, collected from Sichuan and Chongqing, China, were used for karyotypic analyses. The results indicated that both C. chinensis and C. omeinensis were diploid with chromosome 2n = 2x = 18, and C. deltoidea was an autotriploid with chromosomes 2n = 3x = 27, which explained why this species was morphologically so isolated from other species and its sterile and narrow distributing regions. The relationship between C. chinensis and C. omeinensis based on chromosome data was discussed. The probable origin of C. deltoidea was also suggested.
China ; Chromosomes, Plant ; genetics ; Coptis ; genetics ; Diploidy ; Karyotyping

Pterocypsela is a very important traditional Chinese medicine from the tribe Cichorieae of Asteraceae. Mitotic chromosome numbers and karyotypes are reported for P. formosana and P. elata from Hunan and Hubei province, China. The former is new and the latter provide confirmation of previous reference. All P. taxa are diploidy with 2n = 18 and their basic number is tentatively suggested as x = 9. Karyotype of Pterocypsela is 2A and P. formosana with a karyotype formula of 2n = 2x = 18 = 4m + 14sm, and 2n = 2x = 18 = 2m + 8sm +8st for P. elata. It is the first time to report the AI value for Pterocypsela in this paper. Cytological data of chromosomal numbers and karyotypes were used to discuss the close relationships of the Pterocypsela genus and the taxonomy of the medicinal plants.
Asteraceae ; classification ; cytology ; genetics ; Chromosomes, Plant ; genetics ; Diploidy ; Karyotyping

Three-dimensional (3D) genomics is an emerging discipline that studies the 3D spatial structure and function of genomes, focusing on the 3D spatial conformation of genome sequences in the nucleus and its biological effects on biological processes such as DNA replication, DNA recombination and gene expression regulation. The invention of chromosome conformation capture (3C) technology speeds up the research on 3D genomics and its related fields. Furthermore, the development of 3C-based technologies, such as the genome-wide chromosome conformation capture (Hi-C) and chromatin interaction analysis using paired-end tag sequencing (ChIA-PET), help scientists get insight into the 3D genomes of various species. Aims of 3D genomics are to reveal the spatial genome organization, chromosomal interaction patterns, mechanisms underlying the transcriptional regulation and formation of biological traits of microorganism, plant, animal. Additionally, the identification of key genes and signaling pathways associated with biological processes and disease via chromosome 3C technology boosts the rapid development of agricultural science, life science and medical science. This paper reviews the research progress of 3D genomics, mainly in the concept of 3D genomics, the development of chromosome 3C technologies and their applications in agricultural science, life science and medical science, specifically in the field of tumor.
Animals ; Cell Nucleus ; Chromatin/genetics* ; Chromosomes/genetics* ; Genome ; Genomics