Casein and lactose concentrations in milk of 31 species are negatively correlated

Summary Casein and lactose concentrations in milks of various species vary by at least 1–2 orders of magnitude, yet no single species secretes both components at either the high or the low end of the ranges. This pattern of variation could result from evolutionary adaptations in a single secretory mechanism.     

Pupation-temperature range in 12 Drosophila species from different ecological backgrounds

A comparison of pupation-temperature range was made in the laboratory on a temperature gradient (3-38 degrees C) using 12 species of Drosophila representing four species groups and four different ecological backgrounds (temperate-montane forest: virilis group; desert: repleta group; cosmopolitan: melanogaster group; tropical forest: willistoni group). Within groups, differences are found which usually reflect species' distributions. Comparisons of species' mating-, oviposition- and pupation-temperature ranges reveal that pupation most often occurs at temperatures beyond those for mating and oviposition. Each species reflects a different combination of temperature effects. Individual species have different temperature-limits for mating, oviposition and pupation. Temperatures permissive for one response are not predictive of limits on other responses. Among species, temperature can affect a particular response differently. Within groups, species differences can be at high and/or low temperatures for any response, and temperature effects among closely related species can manifest themselves in one, or any combination of responses. One cannot predict which responses will be most and least limited, or at which end of the temperature scale a response will be most limited. Among groups, common, but not absolute temperature ranges generally correspond to the geographic distributions and ecological backgrounds of the species triads. The evaluation of temperature effects on species, based on a single activity, may not be adequate for predicting adaptive strategies.     

Low allozyme and mtDNA variability in the island endemic species Drosophila sechellia (D. melanogaster complex)

Genetic variability of D. sechellia is investigated at both mitochondrial and nuclear levels. The results reveal the existence of a single main type of mtDNA with very few variants and a very low enzyme polymorphism. This situation is consistent with the small population size of this specialized species.     

Low allozyme and mtDNA variability in the island endemic speciesDrosophila sechelia (D. melanogaster complex)

Summary Genetic variability ofD. sechellia is investigated at both mitochondrial and nuclear levels. The results reveal the existence of a single main type of mtDNA with very few variants and a very low enzyme polymorphism. This situation is consistent with the small population size of this specialized species.     

Pupation-temperature range in 12Drosophila species from different ecological backgrounds

Summary A comparison of pupation-temperature range was made in the laboratory on a temperature gradient (3–38°C) using 12 species ofDrosophila representing four species groups and four different ecological backgrounds (temperate-montane forest:virilis group; desert;repleta group; cosmopolitan:melanogaster group; tropical forest:willistoni group). Within groups, differences are found which usually reflect species' distributions. Comparisons of species' mating-, oviposition- and pupation-temperature ranges reveal that pupation most-often occurs at temperatures beyond those for mating and oviposition. Each species reflects a different combination of temperature effects. Individual species have different temperature-limits for mating, oviposition and pupation. Temperatures permissive for one response are not predictive of limits on other responses. Among species, temperature can affect a particular response differently. Within groups, species differences can be at high and/or low temperatures for any response, and temperature effects among closely related species can manifest themselves in one, or any combination of responses. One cannot predict which responses will be most and least limited, or at which end of the temperature scale a response will be most limited. Among groups,common, but notabsolute temperature ranges generally correspond to the geographic distributions and ecological backgrounds of the species triads. The evaluation of temperature effects on species, based on a single activity, may not be adequate for predicting adaptive strategies.     

Evolution of vasopressins in marsupials: a new hormone, phenypressin (Phe2-Arg8-vasopressin), present in the Macropodidae

A duplication of the pressor hormone has been found in some marsupials, either American species belonging to the family Didelphidae or Australian species belonging to the family Macropodidae. Two pressor peptides, lysine vasopressin and phenypressin (Phe2-Arg8-vasopressin) have been chemically identified in the red Kangaroo (Macropus rufus) and the Tammar (Macropus eugenii). In contrast, the brush-tailed Possum (Trichosurus vulpecula), a species belonging to the family Phalangeridae, has a single pressor hormone, arginine vasopressin. Because this latter hormone was also found in a prototherian species, the Echidna, it might be assumed that it is the product of a primitive gene and that a duplication and subsequent mutations led to lysine vasopressin and phenypressin in Macropodidae.     

Structure and function of the fig

Summary An overview is given of the functional anatomy of the fig. The fig is the site of pollination and oviposition, it produces wasps, seeds and pollen, and it is the unit of dispersal. Therefore the fig acts as both a flower and a fruit. When a flower is both fertilized and receives a wasp egg, it eventually produces a wasp. Fertilization in flowers that do not recieve a wasp egg initiates seed production. Wide variation exists in the structural features of figs among different subgenera and sections. Monoecious species and gynodioecious species have different strategies for maintaining the symbiosis with the pollinating fig wasps. Monoecious species produce wasps and seeds in a single fig type and show imperfect heterostyly. Gynodioecious species have specialized figs for wasp and for seed production and are characterized by perfect heterostyly.     

Vision in the ultraviolet

Sensitivity to ultraviolet light (UV) is achieved by photoreceptors in the eye that contain a class of visual pigments maximally sensitive to light at wavelengths <400 nm. It is widespread in the animal kingdom where it is used for mate choice, communication and foraging for food. UV sensitivity is not, however, a constant feature of the visual system, and in many vertebrate species, the UV-sensitive (UVS) pigment is replaced by a violet-sensitive (VS) pigment with maximal sensitivity between 410 and 435 nm. The role of protonation of the Schiff base-chromophore linkage and the mechanism for tuning of pigments into the UV is discussed in detail. Amino acid sequence analysis of vertebrate VS/UVS pigments indicates that the ancestral pigment was UVS, with loss of UV sensitivity occurring separately in mammals, amphibia and birds, and subsequently regained by a single amino acid substitution in certain bird species. In contrast, no loss of UV sensitivity has occurred in the UVS pigments of insects.     

Structure,function and evolution of haspin and haspinrelated proteins,a distinctive group of eukaryotic protein kinases

The haspins constitute a newly defined protein family containing a distinctive C-terminal eukaryotic protein kinase domain and divergent N termini. Haspin homologues are found in animals, plants and fungi, suggesting an origin early in eukaryotic evolution. Most species have a single haspin homologue. However, Saccharomyces cerevisiae has two such genes, while Caenorhabditis elegans has at least three haspin homologues and approximately 16 haspin-related genes. Mammalian haspin genes have features of retrogenes and are strongly expressed in male germ cells and at lower levels in some somatic tissues. They encode nuclear proteins with serine/threonine kinase activity. Murine haspin is reported to inhibit cell cycle progression in cell lines. One of the S. cerevisiae homologues, ALK1, is a member of the CLB2 gene cluster that peaks in expression at M phase and thus may function in mitosis. Therefore, the haspins are an intriguing group of kinases likely to have important roles during or following both meiosis and mitosis.     

Species difference in sensitivity to the diabetogenic action of triphenyltin hydroxide

The sensitivity to the diabetogenic action of triphenyltin hydroxide (TPTOH) was investigated in 5 species of experimental animals. A single oral administration of TPTOH produced marked hyperglycemia and triglyceridemia in rabbits and hamsters, but no evidence of diabetes was found in mice, rats and guinea-pigs. No morphological abnormality was observed in islet tissue from TPTOH-treated hamsters.     

Species difference in sensitivity to the diabetogenic action of triphenyltin hydroxide

Summary The sensitivity to the diabetogenic action of triphenyltin hydroxide (TPTOH) was investigated in 5 species of experimental animals. A single oral administration of TPTOH produced marked hyperglycemia and triglyccridemia in rabbits and hamsters, but no evidence of diabetes was found in mice, rats and guinea-pigs. No morphological abnormality was observed in islet tissue from TPTOH-treated hamsters.     

The genetics of phytotoxin production by plant pathogenic fungi

Little is known about the genetic control of phytotoxin production by plant pathogenic fungi. The production of host-selective toxins known to play a role in disease development has been genetically analyzed in three species ofCochliobolus. InC. heterostrophus, a single genetic locus with two alleles has been identified controlling the production of HMT-toxin. This locus appears to be at or near the breakpoint of a chromosome rearrangement. Single genetic loci have also been identified controlling the production of HC-toxin byC. carbonum and HV-toxin byC. victoriae. The locus inC. carbonum may be a cluster of tightly linked genes.     

Role of toxins in evolution and ecology of plant pathogenic fungi

Many fungal pathogens of plants adapt readily to changes in agriculture. Among the most revealing is a fungal group whose species produce host-selective toxins as key determinants of disease. Several lines of evidence support the hypothesis that these fungi evolved from opportunistic, low-grade pathogens by gaining new genetic information leading to toxin production; in some species, toxin production is known to be under single gene control. as a result of this evolution, these fungi became virulent and host-specialized. The best-known model cases belong to the generaCochliobolus andAlternaria; there are suggestions of evolutionary lines among these genera, with species that range from saprophytes to opportunists to specialized pathogens. Host specialization can lead to genetic isolation, a first step in speciation. Ability to produce host-selective toxin has allowed these fungi to exploit the monocultures and genetic uniformity of modern agriculture. Destructive epidemics have been the result.     

In vivo effects of epinephrine in a freshwater fish

Summary In vivo effects of epinephrine were investigated in a freshwater teleost,Barbus conchonius Hamilton. Fish given 2 mg/kg epinephrine in a single i.m. dose showed significant hypocholesterolemia and elevated, liver and kidney cholesterol levels 1–8 h postinjection. Plasma amino nitrogen evinced a transient yet significant fall at 2 h followed by a significant increase after 24 h. A marked reduction occurred in the plasma FFA and organic PO₄ levels after 1–8 h. The results offer little evidence for a lipolytic effect of epinephrine in this species, and the changes in metabolite levels are attributable, in part, to the catecholamineinduced modification of insulin secretion.N.K. thanks the U.G.C. for the award of a research fellowship.     

The variability of patterns of sexual dimorphism in the hominoid skull

Univariate and multivariate statistical analyses are applied to a number of cranial dimensions and angles from living hominoids in order to investigate the patterns of sexual dimorphism in these groups. Clear differences in patterns of cranial sexual dimorphisms are demonstrated not only between genera but also within a single species (Homo). These differences overlay the common finding of a sexual size difference in all groups. The results imply that caution is required in using the sexual dimorphisms of living hominoids as models for those anticipated in fossils.     

奥杜藻属Audouinella系统分类研究进展

奥杜藻属（Audouinella）是淡水红藻中一个比较重要的类群,主要特征是：藻体为单列细胞组成的分枝丝体,细胞具数个周生盘状色素体,有时边缘浅裂,无蛋白核,可产生单孢子囊进行无性生殖,具有有性生殖过程。已知的种类全部为淡水产。中国淡水奥杜藻属已报道的种类有10种2变种。利用分子生物学手段对我国淡水奥杜藻属进行深入系统的、多特征的分类研究,将是今后研究的主要发展方向。     

Mammalian aldehyde oxidases: genetics, evolution and biochemistry

Mammalian aldehyde oxidases are a small group of proteins belonging to the larger family of molybdo-flavoenzymes along with xanthine oxidoreductase and other bacterial enzymes. The two general types of reactions catalyzed by aldehyde oxidases are the hydroxylation of heterocycles and the oxidation of aldehydes into the corresponding carboxylic acids. Different animal species are characterized by a different complement of aldehyde oxidase genes. Humans contain a single active gene, while marsupials and rodents are characterized by four such genes clustering at a short distance on the same chromosome. At present, little is known about the physiological relevance of aldehyde oxidases in humans and other mammals, although these enzymes are known to play a role in the metabolism of drugs and compounds of toxicological importance in the liver. The present article provides an overview of the current knowledge of genetics, evolution, structure, enzymology, tissue distribution and regulation of mammalian aldehyde oxidases. Received 30 August 2007; received after revision 2 November 2007; accepted 8 November 2007     

The variability of patterns of sexual dimorphism in the hominoid skull

Summary Univariate and multivariate statistical analyses are applied to a number of cranial dimensions and angles from living hominoids in order to investigate the patterns of sexual dimorphism in these groups. Clear differences in patterns of cranial sexual dimorphisms are demonstrated not only between genera but also within a single species (Homo). These differences overlay the common finding of a sexual size difference in all groups. The results imply that caution is required in using the sexual dimorphisms of living hominoids as models for those anticipated in fossils.     

DNA sequence organisation in relation to genome size in birds

Summary DNA sequence interspersion was investigated in pheasant and pelican nuclear DNA. As is typical for birds, these genomes are organized in a long period pattern. Altogether, 5 bird species with genome sizes between 1.6 and 1.9 pg DNA are compared with regard to the extent of repetitive and single copy sequence interspersion. The result indicates that the average length of interspersed repetitive sequences increases with genome size.Acknowledgment. This work was supported by the Deutsche Forschungsgemeinschaft. Mrs H. Tuczynski and Mr J. S. Jackson are thanked for editorial assistance.     

Heat shock proteins in three relatedDrosophila species belonging to theobscura group

The effect of heat shock on protein synthesis in three relatedDrosophila species belonging to theobscura group was analyzed on SDS-acrylamide gels. Four major heat shock proteins (hsps) were found in these species, in which synthesis reaches a maximum at 34°C. Although the higher molecular weight proteins are conserved, differences in size were found for the small hsps in these species. By means of in situ hybridization usingD. melanogaster probes for the small hsp genes, it was inferred that the small hsp genes of theobscura group species are clustered at the 27A locus in all three species.