人类基因定位

基因定位的工作可以向前追溯到本世纪的初期,某些遗传性状或遗传疾病是性连锁遗传,特别是与X染色体相连锁。所以,通过家系调查可以积累证据,确定它们的基因位于X染色体上。关于Y染色体上的基因,除了决定睾丸和H-Y抗原的位点外,基本上还是一无所知。最近十几年来,特别是近5年来,由于体细胞杂交和其它一些新技术的发展,基因定位工作有了较大的发展,人们不仅能对性染色体上的基因定位,而且也能对常染色体上的基因进行定位。人的结构基因(指决定特定蛋白质多肽链上的氨基酸顺序的DNA片段,     

中国人体细胞G式显带染色体的鉴别及模式图

本文提出“中国人体细胞G式显带染色体的鉴别及模式图”。 (一)显带方法 1.湖南医学院医学遗传研究室所用的方法(1973):用外周血和骨髓标本按常规方法培养和滴制染色体玻片标本后,立即置70一80℃烤箱内烤2一3小时,关闭烤箱,让其自然冷却后,按下列程序进行显带:(1)在无菌条件下,用0.8,%NaCI溶液配制0.25多胰蛋白酶溶液,玻璃滤菌器过滤,冰箱保存。(2)将上述0.25铸胰蛋白酶溶液倒人染色缸中,用1 MNaOH调pH至7.0左右,用水浴加温至37℃。(3)将玻片标本投人胰蛋白酶溶液中,不断轻轻地摆动2一3分钟左右。(D取出玻片标本,直立于吸水纸上数秒钟,…     

Natural Selection on Human Y Chromosomes简

In the field of anthropology, the uniparerttally inherited Y chromosome has long been used to trace the paternal lineage of the populations and to understand differences in migration and population genetics between males and females, with additional advantages of small effective population size, suf- ficient markers, and population-specific haplotype distribution （Jobling and Tyler-Smith, 1995; Jin and Su, 2000; Underhill et al., 2000）. Many such population studies have rested on the assumption that all the Y chromosome markers in the non- recombination regions are selectively neutral （Jobling and Tyler-Smith, 2003）.     

The nuclear bodies formed by histone demethylase KDM7A

Dear Editor, In the nucleus of higher eukaryotes, chromatin occupies only a small proportion of the nuclear space, while many proteins and RNAs segregate into membrane-less nuclear bodies (NBs).These NBs follow a stochastic or ordered assembly model and constantly exchange components with the surrounding nucleoplasm (Jain et al., 2016).Typical NBs include nucleoli, nuclear speckles, paraspeckles, PML bodies, Cajal bodies, polycomb bodies and Sam68 bodies,which play critical roles in various biological processes such as ribosome assembly, RNA processing, and protein modification.The dysfunction of nuclear bodies may cause diseases, such as cancer (Li et al., 2019).     

Molecular deconvolution of the neutralizing antibodies induced by an inactivated SARS-CoV-2 virus vaccine

Dear Editor, The rapid emergence and persistence of the pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) has had enormous impacts on global health and the economy.Effective vaccines against SARS-CoV-2 are urgently needed to control the coronavirus disease 2019(COVID-19) pandemic,and multiple vaccines have been found to be efficacious in preventing symptomatic COVID-19(Polack et al.,2020;Wu et al.,2020;Jones and Roy,2021).We have developed a traditional beta-propiolactone-inacti-vated aluminum hydroxide-adjuvanted whole-virion SARS-CoV-2 vaccine (BBIBP-CorV),which elicited protective immune responses in clinical trials (Wang et al.,2020;Xia et al.,2021).The vaccine has been granted conditional approvals or emergency use authorizations (EUAs) in China and other countries.     

Morphogenesis of T-tubules in heart cells: the role of junctophilin-2

The T-tubule (TT) system forms the structural basis for excitation-contraction coupling in heart and muscle cells. The morphogenesis of the TT system is a key step in the maturation of heart cells because it does not exist in neonatal cardiomyocytes. In the present study, we quantified the morphological changes in TTs during heart cell maturation and investigated the role of junctophilin-2 (JP2), a protein known to anchor the sarcoplasmic reticulum (SR) to TT, in changes to TT morphological parameters. Analysis of confocal images showed that the transverse elements of TTs increased, while longitudinal elements decreased during the maturation of TTs. Fourier transform analysis showed that the power of ~2 m spatial components increased with cardiomyocytes maturation. These changes were preceded by increased expression of JP2, and were reversed by JP2 knockdown. These findings indicate that JP2 is required for the morphogenesis of TTs during heart development.     

Secretory/releasing proteome-based identification of plasma biomarkers in HBV-associated hepatocellular carcinoma

For successful therapy, hepatocellular carcinoma (HCC) must be detected at an early stage. Herein, we used a proteomic approach to analyze the secretory/releasing proteome of HCC tissues to identify plasma biomarkers. Serum-free conditioned media (CM) were collected from primary cultures of cancerous tissues and surrounding noncancerous tissues. Proteomic analysis of the CM proteins permitted the identification of 1365 proteins. The enriched molecular functions and biological processes of the CM proteins, such as hydrolase activity and catabolic processes, were consistent with the liver being the most important metabolic organ. Moreover, 19% of the proteins were characterized as extracellular or membrane-bound. For validation, secretory proteins involved in transforming growth factor-β signaling pathways were validated in plasma samples. Alphafetoprotein (AFP), metalloproteinase (MMP)1, osteopontin (OPN), and pregnancy-specific beta-1-glycoprotein (PSG)9 were significantly increased in HCC patients. The overall performance of MMP1 and OPN in the diagnosis of HCC remained greater than that of AFP. In addition, this study represents the first report of MMP1 as a biomarker with a higher sensitivity and specificity than AFP. Thus, this study provides a valuable resource of the HCC secretome with the potential to investigate serological biomarkers. MMP1 and OPN could be used as novel biomarkers for the early detection of HCC and to improve the sensitivity of biomarkers compared with AFP.     

Duck egg drop syndrome virus: an emerging Tembusu-related flavivirus in China

Duck egg drop syndrome virus(DEDSV) is a newly emerging pathogenic flavivirus isolated from ducks in China.DEDSV infection mainly results in severe egg drop syndrome in domestic poultry,which leads to huge economic losses.Thus,the discovery of ways and means to combat DEDSV is urgent.Since 2010,a remarkable amount of progress concerning DEDSV research has been achieved.Here,we review current knowledge on the epidemiology,symptomatology,and pathology of DEDSV.A detailed dissection of the viral genome and polyprotein sequences,comparative analysis of viral antigenicity and the corresponding potential immunity against the virus are also summarized.Current findings indicate that DEDSV should be a distinct species from Tembusu virus.Moreover,the adaption of DEDSV in wildlife and its high homology to pathogenic flaviviruses(e.g.,West Nile virus,Japanese encephalitis virus,and dengue virus),illustrate its reemergence and potential to become a zoonotic pathogen that should not be overlooked.Detailed insight into the antigenicity and corresponding immunity against the virus is of clear significance for the development of vaccines and antiviral drugs specific for DEDSV.     

Time delay and cross-correlated Gaussian noises-induced stochastic stability and regime shift between steady states for an insect outbreak system

In this paper, we focus on investigating the stochastic stability and the regime transition between the endangered state and the boom state for a time-delayed insect growth system driven by correlated external and internal noises. By use of the Fokker Planck equation, the method of small time delay approximation and the fast descent method, we explore in detail the joint action of noise terms and time delay on the mean reproduction and depression time for the insect population. Our investigations indicate that the pseudo-resonance phenomenon of the mean first-passage time (MFPT) occurs because of the impact of different noises and time delay. Through the numerical calculation, it is discovered that multiplicative noise can speed up the shift of the insect population from the boom state to the endangered one, while the noise correlation and time delay can propel the insect system to evolve from the endangered state to the boom state and improve the biological stability. In addition, the impact of the additive noise on the stability of the biological system depends on the positive and negative situation of the noise correlation. On the other hand, during the process of suppressing the insect explosion, it is beneficial to the pest control to amplify the association noise strength and weaken the intensities of the multiplicative, additive noises and time delay. However, during the process of eliminating the pests, it can produce nice effect on the disinsection to increase time delay, the intensities of multiplicative and additive noises and weaken the strength of noise correlation.