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1.
Acetobacterium woodii, Butyribacterium rettgeri, Clostridium barkeri, Clostridium butyricum, Clostridium lituseburense, Eubacterium limosum, andEubacterium tenue have been characterized by oligonucleotide cataloging of their 16S ribosomal RNAs.A. woodii, C. barkeri, andE. limosum form a related group.C. lituseburense andE. tenue are highly related. As previously reported,E. limosum andB. rettgeri are synonymous. TheEubacterium species examined here are less related to each other than they are to different species ofClostridium. Mol% G+C of DNA and murein composition support the 16S ribisomal RNA data. These findings question the validity of current taxonomic distinctions for these Gram-positive anaerobes.  相似文献   

2.
Nereimyra Blainville, 1828 (Psamathini, Hesionidae, Aciculata, Annelida) is revised based on examination of all available types and newly collected specimens. We assessed the phylogeny of Nereimyra in an analysis based on cytochrome oxidase c subunit I (COI), 16S rDNA, 18S rDNA, and 28S rDNA. The genus is delineated to include the three species Nereimyra aphroditoides (Fabricius, 1780), Nereimyra punctata (O.F. Müller, 1776), and Nereimyra woodsholea (Hartman, 1965), which are redescribed. Nereimyra punctata has a characteristic pigmentation, but otherwise there are no clear morphological characters for separating the species. Based on the molecular data we obtained strong support both for the monophyly of Nereimyra and for each of the three included species. Nereimyra punctata and N. woodsholea are sister species, and the Kimura two‐parameter (K2P)‐corrected COI distances between the three species are 16–23%. Syllidia Quatrefages, 1866, is sister group to Nereimyra. Previous uncertainties regarding the type species of the genus are settled to Nereis rosea Fabricius, 1780, junior synonym of N. aphroditoides. A neotype is designated for N. aphroditoides. The distribution of Nereimyra is at present restricted to the Arctic and the boreal parts of the North Atlantic, possibly extending to the Gulf of Mexico on the United States east coast. Records outside this area require verification. Castalia multipapillata Théel, 1879, and Nereimyra alvinae Blake, 1985, are of uncertain affinity and are treated as nomina dubia. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 164 , 36–51.  相似文献   

3.
Karyotypic differences were sought among species of Boykinia, Heuchera, Mitella, Sullivantia, Tiarella, and Tolmiea utilizing a modification of the Hy-banding technique. Prominent centromeric and some telomeric heterochromatin banding was observed. Boykinia aconitifolia and species of Sullivantia possess an identical banded karyotype, while four species of Heuchera, Mitella diphylla, Tiarella cordifolia, and Tolmiea menziesii (the latter at the tetraploid level) are characterized by a second, slightly different banded karyotype. In Sullivantia, Giemsa C-banding stains the same chromosomal regions revealed by Hy-banding. Larger amounts of heterochromatin are present in chromosomes of species of Heuchera, Mitella, Tiarella, and Tolmiea than in chromosomes of Sullivantia species and Boykinia aconitifolia. These karyological observations confirm generic relationships and demonstrate the systematic applicability of chromosome banding techniques to plants with very small chromosomes.  相似文献   

4.
The tettigoniid genus Phlesirtes Bolivar and its allies are reviewed. Morphological, ecological and molecular data prompt the erection of the new genus Chortoscirtes gen.n. with type species Xiphidion meruense Sjöstedt. The genera Phlesirtes, Chortoscirtes, Karniella and Naskreckiella are characterized by morphological characters supported by molecular, acoustic, ecological and chromosomal data. Four species, Chortoscirtes pseudomeruensis sp.n. , C. masaicus sp.n. , C. puguensis sp.n. and C. serengeti sp.n. , are described from localities in northern and coastal Tanzania and one Karniella, K. crassicerca sp.n. , is described from Uganda. The following comb n. are proposed: Phlesirtes kibonotensis (Sjöstedt) and Phlesirtes kilimandjaricus (Sjöstedt). Subtribal status is proposed for the four investigated African genera. A key to the Chortoscirtes species is provided.  相似文献   

5.
This report extends the genetic map of the common shrew (Sorex araneus) by adding chromosome assignments for ten genes to the seven already mapped (Pack et al. 1995). A somatic cell hybrid panel was used for the mapping. The genes for peptidase A (PEPA) and isocitrate dehydrogenase-1 (IDH1) map to chromosome de; the genes for phosphoglucomutase-1 (PGM1), superoxide dismutase-1 (SOD1), and mannosephosphate isomerase (MPI) are located on chromosome af; the genes for nucleoside phosphorylase (NP) and glutathione reductase (GSR) are on chromosome ik; and the genes for peptidase S (PEPS), malic enzyme-1 (ME1), peptidase B (PEPB) are found on chromosomes jl, go, and mp respectively. Received: 2 October 1995 / Accepted: 21 November 1995  相似文献   

6.
Summary Specimens of the blue swimming crab,Portunus pelagicus, are often infected with many thousands of externae ofThompsonia dofleini, all of which are connected through a common root system within the host crab. The species is unique in that the production of sperm cells takes place within the visceral mass of a small minority of the population of the externae. Spermatogonia are probably introduced by male cyprids into these externae when they are young, and they multiply and develop at the expense of the oocytes which rapidly disintegrate and ultimately disappear. It is assumed that the sperm cells are transferred to the ovary of the ordinary, egg-producing externae through the root system. Shortly after the eggs have been fertilized within the ovary they are transferred to the mantle cavity where they develop into cyprid larvae. The larvae become liberated when the externae drop off and the mantle wall disintegrates.Abbreviations used in the figures a annulus - an antennule - bm basal membrane around ovary - ce compound eye - cg cerebral ganglion - cr connecting root - cy cyprid larva(e) - c1 cuticle 1 - c2 cuticle 2 - do degenerating oocytes - e eggs in early division - ec embryonic cells - em embryos - en endocuticle of host - ep epidermis of host - ex exocuticle of host - hc hemocoelic cavity - m mantle - mc mantle cavity - mcy male cyprid - o ovary - oo oocyte - r rupture in wall of visceral mass - rs root system - sc scar - se spawned eggs - so spent ovary - sp spermatogonia - ss sperm and spermatids - st stalk - tc thickened cuticle of mantle cavity - th thorax - vm visceral mass - y yolk granules  相似文献   

7.
The morphological and physiological characters of the species of Blastobotrys, and of a number of similar species of Sporothrix, Trichosporiella and Candida were studied. Blastobotrys is defined as having mother cells (primary conidia) which form distinct, secondary conidia. Sporothix has non-catenulate conidia, or the conidia are catenulate without marked differentiation of conidia of first and second order. Trichosporiella is delimited from Candida by a stronger coherence between hyphal cells, arthroconidia being absent. Four new Blastobotrys species are described, and two unnamed species; two new combinations are proposed in Trichosporiella. Related species in other genera are briefly discussed. A new Stephanoascus teleomorph is described in two strains originally identified as Sp. fungorum. Two diagnostic keys to the described taxa, using either morphological or physiological characters, are given.  相似文献   

8.
A new genus, Altihoratosphaga, is erected for species formerly assigned to Horatosphaga Schaum, 1853, and a new species is described. Four species are included in Altihoratosphaga: Altihoratosphaga nomima (Karsch, 1896), Altihoratosphaga montivaga ( Sjöstedt, 1909 ), Altihoratosphaga nou (Hemp, 2007) and Altihoratosphaga hanangensis sp. nov. All four species are restricted to Tanzanian localities, and, except for A. nomima, for which no ecological data are available, are confined to montane forest habitats. Data on ecology, acoustics, chromosomes, and molecular relationships are provided, as well as a key to Altihoratosphaga species. The present‐day distribution of Altihoratosphaga species suggests former migration events at times when wetter and colder climatic fluctuations favoured connections between montane forest communities, which today are isolated, enabling flightless taxa such as Altihoratosphaga and Monticolaria to spread. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 158 , 66–82.  相似文献   

9.
Abstract: The fossil record of the callianassid genus Glypturus (Decapoda, Axiidea) is re‐evaluated. Our systematic revision, both of extant and fossil taxa, is based on major cheliped morphology only, thus providing an important impetus for palaeontological studies. Both spination and tuberculation of chelipeds are herein considered of great taxonomic importance. Presence of spines on the upper margins of the merus and propodus and the lower margin of the carpus are significant for generic assignment, whereas the extent of tuberculation on lateral surfaces of the propodus is important for assignment at the species level. Altogether, four extant and six exclusively fossil species of Glypturus are recognized. Several extinct callianassid taxa are now transferred to the genus, namely Callianassa berryi, Callianassa fraasi, Callianassa munieri, Callianassa pugnax and Callianassaspinosa; Callianassa pseudofraasi is considered a junior synonym of C. fraasi. Based on a comparison of ecological preferences of extant representatives, the presence of Glypturus in the fossil record is considered to be linked with tropical to subtropical, nearshore carbonate environments of normal salinity. We argue that Glypturus is of Tethyan origin, with a stratigraphical range going as far back as the Eocene. Since then, the genus migrated both westwards and eastwards, establishing present‐day communities in the western Atlantic and Indo‐West Pacific which both comprise several distinct species. In the presumed area of origin, the genus does no longer occur today. The exlusively fossil (middle Eocene) genus Eoglypturus from Italy is considered closely related to Glypturus and is thus assigned to the subfamily Callichirinae as well.  相似文献   

10.
The chromosome numbers of 10 previously uncounted species in Cheilanthes and 1 species of Notholaena are reported. Several confirmatory counts are also listed. One of the plants, Cheilanthes parryi, should probably be retained in the genus Notholaena. Four plants are sexual diploids, three are diploid apomicts, four are triploid apomicts, and three are tetraploids.  相似文献   

11.
Hypotrichs are a highly differentiated and very diverse group of ciliated protists. Their systematics and taxonomy are challenging and call for detailed investigations on their general morphology, ultrastructure, ontogenesis, and molecular phylogeny. Here, a comprehensive study is conducted on a brackish water population of Parabistichella variabilis using light and electron microscopy and phylogenetic analyses based on small subunit ribosomal DNA sequence data. Its morphology, including the infraciliature, pellicle, nuclei, buccal seal, and extrusomes, is documented. The present findings indicate that in P. variabilis: (i) the cortical granules are extrusomes, which differ from those of other hypotrichs; (ii) the buccal seal is bounded by the plasma membrane and contains a single layer of longitudinal microtubules; (iii) two contractile vacuoles might be present rather than one; and (iv) the pharyngeal disks are bounded by a single membrane. Early‐to‐middle stages of ontogenesis are described for the first time, enabling the complete characterization of this process. Phylogenetic analyses indicate that Parabistichella variabilis is closely related to several species from different genera, such as Orthoamphisiella breviseries, Uroleptoides magnigranulosus, and Tachysoma pellionellum. However, ultrastructural and gene sequence data for more taxa are needed in order to resolve the systematics of Parabistichella.  相似文献   

12.
A phylogenetic reconstruction of the Neotropical electric fish genus Hypopygus based on 47 parsimony‐informative morphological characters is presented. A series of synapomorphies support the hypothesis of monophyly of Hypopygus, and partially resolve species‐level relationships within the genus. Hypopygus species are recognized here as miniaturized fishes based on two criteria; first, a derived condition of diminutive body size, and; second, the presence of a suite of reductive morphological characters, including partial or total losses, simplifications, and reductions of the anal‐fin rays, scales, cranial bones, and laterosensory canal system. Reductive characters associated with miniaturization comprise 45% of the total number of characters in the phylogenetic reconstruction of the genus. Miniaturization and reductive morphological evolution in Hypopygus are discussed here in the phylogenetic context. A taxonomic revision of Hypopygus is presented, in which five new species are described, two species previously assigned to the genus are redescribed, and a single known species of Stegostenopos is redescribed and included in Hypopygus as a junior synonym. Distribution maps and a key for all eight valid species of Hypopygus are provided, based on the examination of 5014 catalogued museum specimens. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 163 , 1096–1156.  相似文献   

13.
Scanning electron microscopy and transmitted light microscopy are used in a palynological study of Lophosoria, Metaxya, Sphaeropteris, Alsophila, and Nephelea of the tree fern family Cyatheaceae. The monotypic American genera Lophosoria and Metaxya each have a unique spore morphology which reinforces the taxonomic distinctness of these genera as indicated by their other characters. All investigated paleotropical species of Sphaeropteris develop a single type of perine characterized by coarse, pointed projections. In the neotropics, the Sphaeropteris horrida group shares this perine type, whereas all other neotropical Sphaeropteris species appear to have a different kind of perine with fine hair-like processes. The exine in paleotropical Sphaeropteris appears uniformly unsculptured, whereas in the neotropics several exine morphologies are found. In Alsophila all investigated neotropical species and the vast majority of the paleotropical species are characterized by a basically ridged perine morphology and an unsculptured exine. In several paleotropical Alsophila species, however, a perine with hair-like processes similar to those in neotropical Sphaeropteris is found, and the exine in several species is variously pitted. In at least one paleotropical Alsophila species, the porate exine morphology is indistinguishable from that in the neotropical genus Cnemidaria. The spores of the American genus Nephelea are similar to those of the majority of Alsophila species in ridged perine morphology and unsculptured exine. Several new instances of atypical spore numbers per sporangium are reported in Sphaeropteris and Alsophila. These and the palynological data are discussed in a taxonomic framework. The spore morphology in these genera is consistent with Tryon's recent generic revision of the family.  相似文献   

14.
Angiopoietin‐like proteins (ANGPTLs) are secreted proteins possessing an amino‐terminal coiled‐coil domain and a carboxyl‐terminal fibrinogen‐like domain and are known as angiogenic factors. Several members of ANGPTLs also regulate lipid metabolism independently of angiogenic effects, but most of their functions during vertebrate development are not demonstrated. To ascertain their developmental functions, we examined the expression patterns of Angptl1, 2, 3, 4, 5, and 7 orthologues during chick development using whole‐mount in situ hybridization. Angptl1 was first detected at embryonic day 3 (E3) in the somite. At E4, Angptl1 was expressed in somite‐derivatives and limb mesenchyme. Angptl2 was first detected at E3 in the hindbrain. At E4, Angptl2 was expressed in neuroepithelium of forebrain and hindbrain and partly in the heart. Angptl3 was first detected at E3 and continued to be expressed in the liver and yolk sac at E4. Angptl4 was first detected at E3 in the somites and liver. At E4, Angptl4 was also observed in the heart. Angptl5 was not detected in these developmental stages. Angptl7 was first detected at E3 in the ectoderm overlying the lenses of the eyes. At E4, Angptl7 was specifically expressed in cornea. These data suggest that each member of the ANGPTL family could be related to angiogenesis during various organogeneses of the developing chick embryo.  相似文献   

15.
InMicrocarpaea muscosa gametogenesis, embryo sac development (Polygonum type), endosperm development (cellular), embryogeny (Onagrad type), and seed structure are described. The different modes of endosperm development withinGratioleae are compared.  相似文献   

16.
The carpels of 2 groups of pomoid genera, Amelanchier, Malacomeles, Peraphyllum and Aronia, Malus, Pyrus, and Sorbus, were analyzed morphologically. Open sutures are associated with a lesser extent of tegumentary fusion and ovular bundle–wing bundle fusion than are closed sutures. However, in the genera as a whole (and particularly in Aronia and Sorbus), the extent of sutural closure is inversely related with the amount of intercarpellary adhesion and with the fusion of carpels to the floral cup. In the Amelanchier group and in Malus and Pyrus, ovular- and wing-bundle fusion is directly related with intercarpellary adhesion. Malus and Pyrus have closer structural resemblances with one another than they have with Aronia and Sorbus.  相似文献   

17.
Summary Automated karyotype analyses, nuclear DNA contents, and sequences of rDNA internal transcribed spacers of the nine species inVicia sect.faba are reported. As karyomorphological parameters are used to evaluate the karyotype evolution, so the determination of the heterochromatin by Feulgen absorption at different thresholds of optical density provided further evidence on the chromatin organization withinVicia sect.faba. The comparison of sequences of rDNA spacers has enabled the definition of the phylogenetic relationships between the analyzed species.  相似文献   

18.
Various genes that mapped to the distal end of Chromosome (Chr) 10 were considered as possible candidates for the mouse pygmy (pg) locus. Probes derived from Ifg, Gli, Mdm1, Mdm2 and Mdm3 (Mdm2 and Mdm3 are genes that are coamplified with Mdm1 on the same double minute chromosomes in 3T3DM cells) were used for Southern analysis of DNA from wild-type mice and various pg mutants. In addition, the chromosomal locations of Ifg, Gli, Mdm1, Mdm2, and Mdm3 were determined by interspecific backcross analysis with progeny derived from matings of [(C57BL/6J x Mus spretus)F1 x C57BL/6J] mice. The mapping data indicate that the Mdm loci are linked to each other and to Ifg, pg, and Gli in the distal region of mouse Chr 10. Both the mapping data and the Southern analysis confirm that mdm1, Mdm2, Mdm3, Ifg, and Gli are distinct from pg.  相似文献   

19.
Barnacles of the genus Galkinius occupy a large spectrum of host corals, making it one of the least host‐specific genera within the Pyrgomatidae. Molecular analyses show that within the genus Galkinius there are highly supported clades, suggesting that the genus Galkinius is a complex of evolutionarily significant units (ESUs). The morphology of the opercular valves has been used as the basis for the separation of species of Galkinius. In this study, morphological variability was found both between specimens within ESUs extracted from different host species and between specimens extracted from the same colony. Identifications based on the opercular valves cannot therefore be assigned to different species despite being genetically distinguishable. It is proposed that in many cases the differences between valve morphology of different species of Galkinius are the outcome of ontogeny. Allometric growth of the valves has resulted in differences in the proportions of the parts of the valve. © 2015 The Linnean Society of London  相似文献   

20.
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