New human immunodeficiency virus type 1 (HIV-1) diagnoses are increasing rapidly in Hebei. The aim of this study presents the most extensive HIV-1 molecular epidemiology investigation in Hebei province in China thus far. We have carried out the most extensive systematic cross-sectional study based on newly diagnosed HIV-1 positive individuals in 2013, and characterized the molecular epidemiology of HIV-1 based on full length gag-partial pol gene sequences in the whole of Hebei. Nine HIV-1 genotypes based on full length gag-partial pol gene sequence were identified among 610 newly diagnosed naïve individuals. The four main genotypes were circulating recombinant form (CRF)01_AE (53.4%), CRF07_BC (23.4%), subtype B (15.9%), and unique recombinant forms URFs (4.9%). Within 1 year, three new genotypes (subtype A1, CRF55_01B, CRF65_cpx), unknown before in Hebei, were first found among men who have sex with men (MSM). All nine genotypes were identified in the sexually contracted HIV-1 population. Among 30 URFs, six recombinant patterns were revealed, including CRF01_AE/BC (40.0%), CRF01_AE/B (23.3%), B/C (16.7%), CRF01_AE/C (13.3%), CRF01_AE/B/A2 (3.3%) and CRF01_AE/BC/A2 (3.3%), plus two potential CRFs. This study elucidated the complicated characteristics of HIV-1 molecular epidemiology in a low HIV-1 prevalence northern province of China and revealed the high level of HIV-1 genetic diversity. All nine HIV-1 genotypes circulating in Hebei have spread out of their initial risk groups into the general population through sexual contact, especially through MSM. This highlights the urgency of HIV prevention and control in China.
During spermatogenesis in most animals, the basic proteins associated with DNA are continuously changing and somatic-typed histones are partly replaced by sperm-specific histones, which are then successively replaced by transition proteins and protamines. With the replacement of sperm nuclear basic proteins, nuclei progressively undergo chromatin condensation. The Chinese Mitten Crab (Eriocheir sinensis) is also known as the hairy crab or river crab (phylum Arthropoda, subphylum Crustacea, order Decapoda, and family Grapsidae). The spermatozoa of this species are aflagellate, and each has a spherical acrosome surrounded by a cup-shaped nucleus, peculiar to brachyurans. An interesting characteristic of the E. sinensis sperm nucleus is its lack of electron-dense chromatin. However, its formation is not clear. In this study, sequences encoding histones H3 and H4 were cloned by polymerase chain reaction amplification. Western blotting indicated that H3 and H4 existed in the sperm nuclei. Immunofluorescence and ultrastructural immunocytochemistry demonstrated that histones H3 and H4 were both present in the nuclei of spermatogonia, spermatocytes, spermatids and mature spermatozoa. The nuclear labeling density of histone H4 decreased in sperm nuclei, while histone H3 labeling was not changed significantly. Quantitative real-time PCR showed that the mRNA expression levels of histones H3 and H4 were higher at mitotic and meiotic stages than in later spermiogenesis. Our study demonstrates that the mature sperm nuclei of E. sinensis contain histones H3 and H4. This is the first report that the mature sperm nucleus of E. sinensis contains histones H3 and H4. This finding extends the study of sperm histones of E. sinensis and provides some basic data for exploring how decapod crustaceans form uncondensed sperm chromatin.
Histones and histone phosphorylation play vital roles during animal spermatogenesis and spermatozoa maturation. The dynamic distribution of histones H2A and H4 and phosphorylated H2A and H4 at serine 1 (HS1ph) was explored in mammalian and Decapoda germ cells, with a special focus on the distribution of H2A, H4 and HS1ph between mouse condensed spermatozoa chromatin and crab non-condensed spermatozoa chromatin. The distribution of histone marks was also analysed in mature spermatozoa with different chromatin structures. Histone H2A and H4 marks were closely associated with the relatively loose chromatin structure in crab spermatozoa. The significant decrease in the HS1ph signal during spermatogenesis suggests that eliminating most of these epigenetic marks in the nucleusis closely associated with spermatozoa maturity.
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