Spatial patterns of disparity and diversity of the Recent cuttlefishes (Cephalopoda) across the Old World

Aim Diversity and disparity metrics of all Recent cuttlefishes are studied at the macroevolutionary scale (1) to establish the geographical biodiversity patterns of these cephalopods at the species level and (2) to explore the relationships between these two metrics. Location Sampling uses what is known about these tropical, subtropical and warm temperate cephalopods of the Old World based on a literature review and on measurements of museum specimens. Some 111 species spread across seventeen biogeographical areas serve as basic units for exploring diversity and disparity metrics in space. Methods Landmarks describe the shape of the cuttlebone (the inner shell of the sepiids) and differences between shapes are quantified using relative warp analyses. Relative warps are thus used as the morphological axis for constructing morphospaces whose characteristics are described by disparity indices: total variance, range, and minimum and maximum of relative warps. These are analysed and then compared with the diversity (species richness) metric. Results Results show no significant latitudinal or longitudinal gradients either for diversity or for disparity. Around the coast of southern Africa, disparity is high regardless of whether diversity (species richness) is high or low. In the ‘East Indies’ area disparity is low despite the high diversity. Main conclusions The relationship between diversity and disparity is clearly not linear and no simple adjustment models seem to fit. The number of species in a given area does not predict its disparity level. The particular pattern of southern Africa may be the result of paleogeographical changes since the Eocene, whereas that of the ‘East Indies’ may indicate that this area could act as a centre of origin. However, the lack of any clear phylogenetical hypothesis precludes the study from providing any explanation of the observed patterns.     

Simian Varicella in Old World Monkeys

Simian varicella virus (SVV) causes a natural erythematous disease in Old World monkeys and is responsible for simian varicella epizootics that occur sporadically in facilities housing nonhuman primates. This review summarizes the biology of SVV and simian varicella as a veterinary disease of nonhuman primates. SVV is closely related to varicella–zoster virus, the causative agent of human varicella and herpes zoster. Clinical signs of simian varicella include fever, vesicular skin rash, and hepatitis. Simian varicella may range from a mild infection to a severe and life-threatening disease, and epizootics may have high morbidity and mortality rates. SVV establishes a lifelong latent infection in neural ganglia of animals in which the primary disease resolves, and the virus may reactivate later in life to cause a secondary disease corresponding to herpes zoster. Prompt diagnosis is important for control and prevention of epizootics. Antiviral treatment for simian varicella may be effective if administered early in the course of infection.Abbreviations: FEAU, 1-(2′-deoxy-2′-flouro-β-D-arabinofuranosyl)-5-iodouracil, IE, immediate early, ORF, open reading frame, PBL, peripheral blood lymphocyte, SVV, simian varicella virus, VZV, varicella–zoster virusSimian varicella is a natural erythematous disease of Old World primates (Superfamily Cercopithecoidea, Subfamily Cercopithecinae), involving particularly patas (Erythrocebus patas), African green or vervet (Chlorocebus aethiops), and various species of macaque (Macaca spp.) monkeys. Epizootics of simian varicella occur sporadically in facilities housing nonhuman primates. These outbreaks are sometimes associated with high morbidity and mortality and the loss of valuable research animals. Simian varicella virus (SVV; Cercopithecine herpesvirus 9), a primate herpesvirus, is the etiologic agent of the disease. SVV is antigenically and genetically related to varicella–zoster virus (VZV; Human herpesvirus 3), the cause of human varicella (chickenpox) and herpes zoster (shingles). The clinical similarities between simian and human varicella and the relatedness of SVV and VZV, indicate that SVV infection of nonhuman primates is a useful model for study of varicella pathogenesis and development of antiviral therapies. A previous comprehensive review emphasized simian varicella as an experimental model for VZV infections.²² This review focuses on simian varicella as a veterinary disease of nonhuman primates. Simian varicella outbreaks and their epidemiology are considered, and the etiologic agent, clinical manifestations, pathogenesis, diagnosis, treatment, and control of the disease are discussed.     

Geographic distribution of haplotype diversity at the bovine casein locus

The genetic diversity of the casein locus in cattle was studied on the basis of haplotype analysis. Consideration of recently described genetic variants of the casein genes which to date have not been the subject of diversity studies, allowed the identification of new haplotypes. Genotyping of 30 cattle breeds from four continents revealed a geographically associated distribution of haplotypes, mainly defined by frequencies of alleles at CSN1S1 and CSN3. The genetic diversity within taurine breeds in Europe was found to decrease significantly from the south to the north and from the east to the west. Such geographic patterns of cattle genetic variation at the casein locus may be a result of the domestication process of modern cattle as well as geographically differentiated natural or artificial selection. The comparison of African Bos taurus and Bos indicus breeds allowed the identification of several Bos indicus specific haplotypes (CSN1S1*C-CSN2*A²-CSN3*A_I/CSN3*H) that are not found in pure taurine breeds. The occurrence of such haplotypes in southern European breeds also suggests that an introgression of indicine genes into taurine breeds could have contributed to the distribution of the genetic variation observed.     

Brain evolution in Old World monkeys.

Sulcal patterns of 14 genera of Old World monkeys were analyzed from 107 endocasts. Colobines and cercopithecines differ in patterns of cerebral convolutions, and functional and evolutionary hypotheses are here proposed regarding those differences. The cercopithecine pattern seems to be the more derived since it suggests relative expansion of prefrontal, and inferior temporal integration cortices as compared to the colobine pattern.     

Cerebral asymmetry in Old World monkeys.

A photogrammetric computer analysis of 88 endocasts, representing 8 genera of Old World monkeys, reveals cortical asymmetry in lengths of the Sylvian fissure, superior temporal sulcus, lateral edge of the orbit and distance separating rectus and arcuate sulci. Hypothetical expansion of left prefrontal and parietal integration cortices explains these asymmetries.     

Evolutionary rate variation in Old World monkeys

We analysed over 8 million base pairs of bacterial artificial chromosome-based sequence alignments of four Old World monkeys and the human genome. Our findings are as follows. (i) Genomic divergences among several Old World monkeys mirror those between well-studied hominoids. (ii) The X-chromosome evolves slower than autosomes, in accord with ‘male-driven evolution’. However, the degree of male mutation bias is lower in Old World monkeys than in hominoids. (iii) Evolutionary rates vary significantly between lineages. The baboon branch shows a particularly slow molecular evolution. Thus, lineage-specific evolutionary rate variation is a common theme of primate genome evolution. (iv) In contrast to the overall pattern, mutations originating from DNA methylation exhibit little variation between lineages. Our study illustrates the potential of primates as a model system to investigate genome evolution, in particular to elucidate molecular mechanisms of substitution rate variation.     

Reproductive physiology in female Old World Camelids

This review summarizes the basic reproductive physiology of dromedary and Bactrian camels. Camels are seasonal breeders with a relatively short breeding season during the cooler months. The onset of the breeding season can be influenced by local environmental factors such as temperature and pasture availability although decreased libido of the male as the environmental temperature increases is also a factor. Oestrous behaviour is highly variable in duration and intensity and is therefore unreliable for the detection of oestrus and difficult to relate to follicular activity in the ovaries. Camels are induced ovulators and thus normally only ovulate in response to mating. In the absence of mating, ovarian follicles tend to regress after a period of growth and maturity, whereas if male and females are kept together the female gets mated when the dominant follicle measures between 1.3 and 1.7 cm in diameter and the corpus luteum that develops has a lifespan of only 10-12 days. Peripheral concentrations of oestradiol increase with increasing follicle diameter until the follicle reaches 1.7 cm in diameter at which time they start to decrease even if the follicle continues to grow. The concentrations of progesterone remains low in non-mated animals but in mated camels it increases 3-4 days after ovulation (day of ovulation=Day 0) to reach maximum concentrations on Days 8-9 before decreasing rapidly on Days 10-11 in the non-pregnant animal. Ovulation can also be reliably induced using either Gonadotrophin Releasing Hormone (GnRH) or human Chorionic Gonadotrophin (hCG) but only when the follicle measures between 1.0 and 1.9 cm in diameter. Ovulation does not typically occur from follicles that grow beyond 2.0 cm in diameter but these follicles typically develop echogenic strands of fibrin as the follicle degenerates. The gestation period of camels is 13 months but the time of resumption of follicular activity following parturition is highly variable and influenced by nutritional status and lactation. Females that lose their offspring or have offspring which are weaned have a mature follicle develop within 10-12 days, whilst in well-fed lactating females mature follicles do not develop until 30-60 days postpartum.     

The phylogeny of Old World monkeys

The living Old World monkeys, family Cercopithecidae, are the most successful group of nonhuman primates alive today. Overall, they account for over one quarter of the extant genera of primates and approximately 40% of the species. They have an extensive fossil record extending back to the early and middle Miocene of Africa.^1,2 Despite this specific diversity and a long evolutionary history, it is commonly argued that the group is relatively uniform in both its skeletal³ and dental⁴ anatomy, suggesting that much of the current taxonomic diversity is a relatively recent phenomenon. In such a species group, it is perhaps not surprising that the taxonomy of Old World monkeys is subject to many differing classifications. Thus, in recent years, authors have recognized as few as 10 and as many as 22 different genera within the family. Although some of this greater-than-two-fold difference in the number of genera can be attributed to the “splitting” versus “lumping” philosophies of different researchers, much of it is based on major disagreements over phylogenetic relationships. Recent studies of the genetics and chromosomes of this group have illuminated Old World monkey phylogeny in many ways. Some of these studies have resolved longstanding debates based on morphological data; others have revealed phylogenetic relationships that morphologists had never suspected.     

Jaw muscles of Old World squirrels

The jaw, suprahyoid, and extrinsic tongue muscles were studied in 11 genera, belonging to five tribes, of Old World squirrels. Significant variation in most of the adductor muscles is evident. The most primitive state of sciuromorphy is seen in the African tree squirrels Paraxerus and Funisciurus, especially as reflected in the anterior deep masseter. A derived state of sciuromorphy is found in five genera of Old World squirrels and perhaps evolved independently in each. Reduction of the temporalis muscle was observed in three genera, distantly related to one another. A unique arrangement of the superficial masseter is reported in the Asian giant tree squirrels, Ratufa. The arrangement of the masseter in the African pygmy squirrel, Myosciurus, is very similar to that of the South American pygmy squirrel, Sciurillus. We present hypotheses about the functional significance of these differences. In the derived state of sciuromorphy, which is found in three cases in squirrels that feed extensively on hard fruits, the anterior deep masseter is well positioned to increase the strength of the power stroke of the incisor bite. Among the pygmy squirrels, the position of the anterior deep masseter suggests that it plays a more significant role in molar chewing. © 1996 Wiley-Liss, Inc.

1 This article is a US Government work and, as such, is in the public domain in the United States of America.

     

乳糖酶研究进展

乳糖酶作为乳品添加剂,应用相当广泛,通过来源及其性质、基础研究和应用等方面对乳糖酶进行综述,重点介绍乳糖酶研究上的新进展和应用的新领域,由于近年来低温乳糖酶成为研究热点,特别对低温乳糖酶的研究进行介绍.