The Hardy-Weinberg principle and its applications in modern population genetics

The discovery of the Hardy-Weinberg principle marked the beginning of the field of population genetics. Over the past hundred years, it has provided a starting point for many population genetic investigations. In this review, the Hardy-Weinberg principle, its statistical testing, and several of its applications in various modern population genetic research areas, including allelic variability and selection in the human leukocyte antigen region, microsatellite genotyping error detection, and accuracy of haplotype estimation, are discussed.     

Rotifer genetics: integration of classic and modern techniques

Rotifer genetics has a long but sporadic history. There have been 4 major periods of research activity: (1) determining the environmental control of sexuality with inferences regarding genetics — early 1900's; (2) exploring the relationship between chromosome numbers and the rotifer life cycle — 1920's; (3) physiological and developmental genetics — 1960's; and (4) theoretical and experimental population genetics late 1970's. With newly developed molecular techniques, in conjunction with more traditional approaches, integration of these fields is beginning. Examples include investigation of gene expression involved in sexual reproduction by isolating glycoproteins responsible for mate recognition. Improvement of techniques for chromosome analysis has made it possible to verify haploidy in males and led to the discovery of polyploidy. The role of specialized proteins in the stress response is being elaborated with an accompanying search for the genetic elements which control them. Most recently the polymerase chain reaction (PCR) has been used to amplify ribosomal genes, and is a first step in using DNA sequences to define evolutionary relationships among the Rotifera.     

Chia-Chen Tan and genetics in modern China

Chia-Chen Tan(谈家桢,1909-2008)was one of the most important founders of genetics in modern China and made great effort to the inter nation alization of Chinese gen etics(Fig.1).Chia-Chen Tan was born on September 15,1909 in Zhejiang Provinee.He studied in missionary middle school and public high school successively before being admitted to Soochow Un iversity without exami nation.He majored in biology in university and became interested in genetics.After graduating in 1930,he entered YenChing University and learnt from Ju-Chi Li(李汝祺)(Fig.2)who was the first Chinese student to receive a doctor's degree from American famous geneticist Thomas Hunt Morgan and was the only genetics professor in YenChing University at that time(Zhang,2017).     

Mycobacteria in the light of modern genetics development

It is generally assumed that genetic research of mycobacteria is delayed as compared with other, more commonly used, bacterial models, particularly in the field of genetic transfers. In the field of mutagenesis the problems have been studied to such an extent that replication maps of the chromosome of M. phlei and M. tuberculosis H37 Rv have already been constructed and a new model of the cell cycle of bacteria exhibiting a slow growth rate has been worked out. When the problems of mycobacterial genetics are looked upon in the light of gene manipulations it may be concluded that mycobacteria belong to a few models whose genes are used for cloning and that problems of practical significance will be studied by means of the most modern approaches.     

An optimizing principle of natural selection in evolutionary population genetics

This paper brings together two themes in evolutionary population genetics theory. The first concerns Fisher's Fundamental Theorem of Natural Selection: a recent interpretation of this theorem claims that it is an exact result, relating to the so-called "partial" increase in mean fitness. The second theme concerns the desire to find an optimality principle in genetic evolution. Such a principle is found here: of all gene frequency changes which lead to the same partial increase in mean fitness as the natural selection gene frequency changes, the natural selection values minimize a generalized distance measure between parent and daughter generation gene frequency values.     

The role of empirical Bayes methodology as a leading principle in modern medical statistics

This paper reviews and discusses the role of Empirical Bayes methodology in medical statistics in the last 50 years. It gives some background on the origin of the empirical Bayes approach and its link with the famous Stein estimator. The paper describes the application in four important areas in medical statistics: disease mapping, health care monitoring, meta‐analysis, and multiple testing. It ends with a warning that the application of the outcome of an empirical Bayes analysis to the individual “subjects” is a delicate matter that should be handled with prudence and care.     

N. I. Vavilov's law of genetic homology in modern genetics

The paper considers the place in modern genetics and the significance of the main N.I. Vavilov's generalization--his law of homologous series in variation. Recent analysis of amino acid sequences of gene products (proteins) and especially of nucleotide sequences of genes shows the high degree of molecular homology between genes of closely related species and the retention of the homology through the course of evolution. The study of homologous genes disposition in chromosomes shows conservation of the similar orders of genes in many organisms, especially in mammals. Thus, the law of genetic homology has been confirmed by modern genetic researchers. It is a foundation-stone of comparative genetics--new and rapid developing branch of genetics which involves studies on similarity and differences in heredity and variation in organisms of different taxa.     

Craniosynostosis genetics: The mystery unfolds

Craniosynsostosis syndromes exhibit considerable phenotypic and genetic heterogeneity. Sagittal synostosis is common form of isolated craniosynostosis. The sutures involved, the shape of the skull and associated malformations give a clue to the specific diagnosis. Crouzon syndrome is one of the most common of the craniosynostosis syndromes. Apert syndrome accounts for 4.5% of all craniosynostoses and is one of the most serious of these syndromes. Most syndromic craniosynostosis require multidisciplinary management. The following review provides a brief appraisal of the various genes involved in craniosynostosis syndromes, and an approach to diagnosis and genetic counseling.