Canine behavioral genetics — A review

A chronological review of the history of research in canine behavioral genetics is presented. Prior to the work of Scott and Fuller, many studies attempted to describe observed results in simple Mendelian terms. More recently, a quantitative mode of inheritance has been ascribed to many behavioral traits, and heritabilities have been calculated in different populations. Studies of behavioral traits are complicated by the effects of learning, which may well explain the reports of low heritability of behavioral traits measured on adults. Both genotype and environment have been shown to play major roles in the expression of behavioral traits. Maternal effects and the sex of an individual have important effects on behavior scores. Breeders usually select for both physical and behavioral traits in the same individuals, and this review includes a summary of reported research on the relationships between physical and mental traits.     

Rye cytology,cytogenetics and genetics — current status

Summary Progress in rye karyology is reviewed with respect to chromosome structure, recognition and chromosome nomenclature. Considerable contributions have been brought about by molecular techniques which have even revealed nucleotide sequences of some of the ribosomal DNA. DNA sequence organization correlates with the distribution of major Giemsa C-band regions as well as with N-bands and the binding sites of fluorescent dyes. The several banding patterns permit the classification of rye chromosomes. The increased data and widespread application of banding analysis require a consistent system of chromosome and/or band designation. Therefore, a standard band nomenclature is proposed with reference to the recommendations of the Paris Conference on Standardization in Human Cytogenetics. In addition, advances in genetics are summarized and discussed. Based on the original accepted standard karyogram and banding patterns of the rye chromosomes, meanwhile, 120 genes determining several characters have been associated with individual chromosomes and/or chromosome arms, including linkage studies for about 19 arrangements. Most results were obtained using wheat-rye addition lines as well as test crosses with defined translocations. Moreover, genetical studies based on appropriate trisomic and telotrisomic material resulted in the localization of 19 genes, including their linkage relationships.     

The genetics of aniridia — simple things become complicated

Aniridia is a rare, panocular disorder characterized by a variable degree of hypoplasia or the absence of iris tissue associated with additional ocular abnormalities. It is inherited in an autosomal dominant manner, with high penetrance and variable expression even within the same family. In most cases the disease is caused by haploinsufficiency truncating mutations in the PAX6 gene; however, in up to 30% of aniridia patients, disease results from chromosomal rearrangements at the 11p13 region. The aim of this review is to present the clinical and genetic aspects of the disease. Furthermore, we present a molecular diagnostic strategy in the aniridia patients. Recent improvement in the genetic diagnostic approach will precisely diagnosis aniridia patients, which is essential especially for children with aniridia in order to determine the risk of developing a Wilms tumor or neurodevelopmental disorder. Finally, based on the previous studies we describe the current knowledge and latest research findings in the topic of pathogenesis of aniridia and possible future treatment.     

Molecular genetics of preeclampsia and HELLP syndrome — A review

Preeclampsia is characterised by new onset hypertension and proteinuria and is a major obstetrical problem for both mother and foetus. Haemolysis elevated liver enzymes and low platelets (HELLP) syndrome is an obstetrical emergency and most cases occur in the presence of preeclampsia. Preeclampsia and HELLP are complicated syndromes with a wide variety in severity of clinical symptoms and gestational age at onset. The pathophysiology depends not only on periconceptional conditions and the foetal and placental genotype, but also on the capability of the maternal system to deal with pregnancy. Genetically, preeclampsia is a complex disorder and despite numerous efforts no clear mode of inheritance has been established. A minor fraction of HELLP cases is caused by foetal homozygous LCHAD deficiency, but for most cases the genetic background has not been elucidated yet. At least 178 genes have been described in relation to preeclampsia or HELLP syndrome. Confined placental mosaicism (CPM) is documented to cause early onset preeclampsia in some cases; the overall contribution of CPM to the occurrence of preeclampsia has not been adequately investigated yet. This article is part of a Special Issue entitled: Molecular Genetics of Human Reproductive Failure.     

Cotton variant genomes—a breakthrough in population genetics analysis

正Cotton is not only an important cash crop for its fiber,but also an excellent model system for studying polyploidization,cell elongation and cell wall biosynthesis(Yang et al.,2014;Fang et al.,2017;Wang et al.,2016;Zou et al.,2016).A focus for scientists is to dissect the genetic basis underlying important agronomic traits(Gong et al.,2018;Huang et al.,2016).The advent of high-throughput sequencing technologies has boosted unveiling the cotton genome(Wang et al.,2012;Li et al.,2014;Li et al.,2015).High-throughput     

Agaroids from New Zealand members of the Gracilariaceae (Gracilariales,Rhodophyta) — a novel dimethylated agar

Polysaccharide extracts from four New Zealand members of the Gracilariaceae have been characterized by ¹³C-NMR spectroscopy and GLC analysis of alditol acetate derivatives prepared using a new double hydrolysis-reduction procedure. All were based on variously substituted repeating disaccharide units of agarobiose and 20% of its precursor containing l-galactose-6-sulfate. Gracilaria truncata yielded a firm gelling agar with 67% methylation on the 6-position of the d-galactose residues. The other extracts belong to a new class of agar molecules having methylation on both the 6-position of the d-galactose units and the 2-position of the l-sugar units. The Curdiea coriacea polysaccharide displayed this double methylation almost completely ( 96 %); the alkali-modified polymer thus had only two free hydroxy-groups per disaccharide repeat unit, yet still gave a firm gel. The Curdiea flabellata and Melanthalia abscissa extracts had this double methylation pattern but to a lesser extent, and additional xylosyl branch units on up to 18% of the repeating disaccharide units.     

Sustainable systems as organisms?

Schrödinger [Schrödinger, E., 1944. What is Life? Cambridge University Press, Cambridge] marvelled at how the organism is able to use metabolic energy to maintain and even increase its organisation, which could not be understood in terms of classical statistical thermodynamics. Ho [Ho, M.W., 1993. The Rainbow and the Worm, The Physics of Organisms, World Scientific, Singapore; Ho, M.W., 1998a. The Rainbow and the Worm, The Physics of Organisms, 2nd (enlarged) ed., reprinted 1999, 2001, 2003 (available online from ISIS website www.i- sis.org.uk)] outlined a novel “thermodynamics of organised complexity” based on a nested dynamical structure that enables the organism to maintain its organisation and simultaneously achieve non-equilibrium and equilibrium energy transfer at maximum efficiency. This thermodynamic model of the organism is reminiscent of the dynamical structure of steady state ecosystems identified by Ulanowicz [Ulanowicz, R.E., 1983. Identifying the structure of cycling in ecosystems. Math. Biosci. 65, 210–237; Ulanowicz, R.E., 2003. Some steps towards a central theory of ecosystem dynamics. Comput. Biol. Chem. 27, 523–530].The healthy organism excels in maintaining its organisation and keeping away from thermodynamic equilibrium – death by another name – and in reproducing and providing for future generations. In those respects, it is the ideal sustainable system. We propose therefore to explore the common features between organisms and ecosystems, to see how far we can analyse sustainable systems in agriculture, ecology and economics as organisms, and to extract indicators of the system's health or sustainability.We find that looking at sustainable systems as organisms provides fresh insights on sustainability, and offers diagnostic criteria for sustainability that reflect the system's health.In the case of ecosystems, those diagnostic criteria of health translate into properties such as biodiversity and productivity, the richness of cycles, the efficiency of energy use and minimum dissipation. In the case of economic systems, they translate into space-time differentiation or organised heterogeneity, local autonomy and sufficiency at appropriate levels, reciprocity and equality of exchange, and most of all, balancing the exploitation of natural resources – real input into the system – against the ability of the ecosystem to regenerate itself.     

Nageiaceae—A New Gymnosperm Family

A new monotypic gymnosperm family, Nageiaceae D. Z. Fu, is separated from Podocarpaceae. It is characterized by having multinerved leaves without costae, and primitive shoot-like female reproductive organs (female strobili). The new family contains a single genus consisting of 2 sections, 5 species and is distributed along the western coast of the Pacific, from low coastal mountains of eastern and southern Asia to the Phillipines and Papua New Guinea. The first species in the Nageiaceae was described as an angiosperm, Myrica nagi Thunb. (1784), but it was soon recognized to be a gymnosperm belonging to a new genus, and was renamed as Nageia japonica Gaert. (1788). The generic name, Nageia, however, has seldom been used, and the members of Nageia have generally been treated as an isolated section of Podocarpus in the Podocarpaceae. When revising the Podocarpaceae, De Laubenfels (1969) established a new genus Decussocarpus based on Nageia, but several years later (1987) he revived the old generic name, Nageia. Page ( 1988,1990)considered Nageia to be a valid generic name and redefined it as a natural genus. The distinctive,broadly lanceolate, multinerved leaves (without costae) of Nageia are rather unusual in gymnosperms,only being similar to those of Agathis in the Araucariaceae, their leaves are also similar to each other in anatomy. For example, there are many single vascular bundles arranged parallelly, between which occur sclerenchyma cells in the mesophyll. Apparently,leaves in Nageia are rather similar both externally and internally to paleogymnosperm cordaitean leaves, and sclerenchyma cells found in Nageia might be the remains of straps between veins in cordaitean leaves. In addition to leaf characters, the large and nearly round pith of the young shoot in Nageia appears to be a reminiscent of the large pith in cordaitean stem. The female reproductive organs (female strobili ) in Nageia are shoot-like. The female strobilus has a sterile terminal bud, and several opposite or subopposite sterile scaly bracts on its axis; two opposite megasporophylls are found near the axis apex and both have an anatropous ovule which is almost entirely covered by the megasporophyll; a bract is partly adnate to the lower back of the megasporophyll;mature arillate seeds are 1-2 or occasionally 3 in number; the axis becomes woody when the seeds mature, but in some species (N. wallichiana) the upper part of the axis becomes fleshy (in the shape of a receptacle), in which no distinct boundary was found between the fleshy receptacle and the woody part, and both have the same scaly bracts or traces. Many characters in Nageia are distinctly different from those in Podocarpus. Leaves in the Podocarpaceae have distinct midribs; in Podocarpus, the reproductive organ, which was generally thought to be similar to that in Nageia, has no terminal bud, and its bract is entirely free from the lower back of the megasporophyll, the fleshy receptacle is derived from both the axis and the sterile bracts (except the lowest two), and the female strobilus at the seed stage has a secondary stalk. The multinerved leaf in Nageia can rarely be found in most of the living gymnosperms except in some rather isolated groups, such as Araucariaceae, Ephedraceae,Ginkgoaceae and Welwitschiaceae. Paleobotanical evidence shows that multinerved leaves have been found in all of the geological ages from the Paleozoic to the present, and such a shoot-like female reproductive organ as in Nageia was found in some paleogymnosperms. It is very difficult to determine the systematic positions of these fossil plants because of lacks adequate material of reproductive organs or even lack of complete vegetative organs. The vascular system and leaf characters of gymnosperms are considered to be very conservative, and the fact that the common leaf shape and venation exist in both fossil and living gymnosperms could imply that there exists a multinerved-leaved evolutionary line ( M-line ) in gymnosperms, which could be traced back to the paleogymnosperm cordaitean plants or even older ones with multinerved leaves. The different types of the female strobili (female reproductive organs) of living gymnosperms, regardless of having one or only several seeds without a typical cone or many seeds with a cone, might have been derived from shoot-like or spikelike female reproductive organs possessed by their common ancestor.The fossil eviden ce shows that the typical cone similar to those of living gymnosperms first appeared in the Jurassic, much later than the single-seeded fossil plant without cones. The seed fossil appeared in the late Devonian Period. It is very difficult to infer the relationships among living gymnosperms, which are hardly derived from one another. But an analysis of the strobili, including the axis structure and position, number, morphology and degree of adnation of the phyllomes on them, would be helpful to the study of their phylogeny. It is evident, therefore, that the gymnosperms with leaves having a midrib might also have a rather long evolutionary course,but no transition between the midrib and multinerved patterns of leaf venation has so far been found in both living and fossil plants. Finally, it is noteworthy that the Nageiaceae are distributed along the western coast of the Pacific, where many primitive representatives, both in gymnosperms and angiosperms, still survive. This would be advantageous to the consideration of Nageiaceae as a primitive representative, or a descendant of fhe paleogymnos-perm cordaitean plants.