Phylogeny of the bears (Ursidae) based on nuclear and mitochondrial genes

The taxomic classification and phylogenetic relationships within the bear family remain argumentative subjects in recent years. Prior investigation has been concentrated on the application of different mitochondrial (mt) sequence data, herein we employ tw

Phylogenetic studies of pantherine cats (Felidae) based on multiple genes, with novel application of nuclear beta-fibrinogen intron 7 to carnivores

The pantherine lineage of the cat family Felidae (order: Carnivora) includes five big cats of genus Panthera and a great many midsized cats known worldwide. Presumably because of their recent and rapid radiation, the evolutionary relationship among pantherines remains ambiguous. We provide an independent assessment of the evolutionary history of pantherine lineage using two complete mitochondrial (mt) genes (ND2 and ND4) and the nuclear beta-fibrmogen intron 7 gene, whose utility in carnivoran phylogeny was first explored. The available four mt (ND5, cytb, 12S, and 16SrRNA) and two nuclear (IRBP and TTR) sequence loci were also combined to reconstruct phylogeny of 14 closely related cat species. Our analyses of combined mt data (six genes; approximate to 3750 bp) and combined mt and nuclear data (nine genes; approximate to 6500 bp) obtained identical tree topologies, which were well-resolved and strongly supported for almost all nodes. Monophyly of Panthera genus in pantherine lineage was confirmed and interspecific affinities within this genus revealed a novel branching pattern, with P. tigris diverging first in Panthera genus, followed by P. onca, P. leo, and last two sister species P. pardus and P. uncia. In addition, close association of Neofelis nebulosa to Panthera, the phylogenetic redefinition of Otocolobus manil within the domestic cat group, and the relatedness of Acinonyx jubatus and Puma concolor were all important findings in the resulting phylogenies. The potential utilities of nine different genes for phylogenetic resolution of closely related pantherine species were also evaluated, with special interest in that of the novel nuclear beta-fibrinogen intron 7. (c) 2005 Elsevier Inc. All rights reserved.

Molecular phylogeny of the Drosophila virilis section (Diptera : Drosophilidae) based on mitochondrial and nuclear sequences

Regardless of the well-documented virilis species group, most groups of the Drosophila virilis section have not been completely studied at molecular level since it was suggested. Therefore, phylogenetic relationships among and within species groups of the

Phylogeny of Raninae (Anura : Ranidae) inferred from mitochondrial and nuclear sequences

Phylogenetic relationships among representative species of the subfamily Raninae were investigated using approximately 2000 base pairs of DNA sequences from two mitochondrial (12S rRNA, 16S rRNA) and two nuclear (tyrosinase, rhodopsin) genes. Phylogenetic

Molecular phylogeny of the Chinese ranids inferred from nuclear and mitochondrial DNA sequences

The phylogeny of representative species of Chinese ranids was reconstructed using two nuclear (tyrosinase and rhodopsin) and two mitochondrial (12S rRNA, 16S rRNA) DNA fragments. Maximum parsimony, Bayesian, and maximum likelihood analyses were employed.-

Phylogenetic incongruence between nuclear and mitochondrial markers in the Asian colobines and the evolution of the langurs and leaf monkeys

Evidence of incongruence between mitochondrial and nuclear gene trees is now becoming documented with increasing frequency. Among the Old World monkeys, this discordance has been well demonstrated in the Cercopithecinae, but has not yet been investigated

New insights to the molecular phylogenetics and generic assessment in the Rhacophoridae (Amphibia: Anura) based on five nuclear and three mitochondrial genes, with comments on the evolution of reproduction

The phylogenetic relationships among 12 genera of treefrogs (Family, Rhacophoridae), were investigated based on a large sequence data set, including five nuclear (brain-derived neurotrophic factor, proopiomelanocortin, recombination activating gene 1, tyr

Duplication-degeneration as a mechanism of gene fission and the origin of new genes in Drosophila species

Gene fission and fusion, the processes by which a single gene is split into two separate genes and two adjacent genes are fused into a single gene, respectively, are among the primary processes that generate new genes(1-4). Despite their seeming reversibi

A comparative approach to somatic cell nuclear transfer in the rhesus monkey

BACKGROUND: Despite the potential utility of primate somatic cell nuclear transfer (SCNT) to biomedical research and to the production of autologous embryonic stem (ES) cells for cell- or tissue-based therapy, a reliable method for SCNT is not yet availab

Reprogramming following somatic cell nuclear transfer in primates is dependent upon nuclear remodeling

BACKGROUND: Somatic cell nuclear transfer (SCNT) requires cytoplast-mediated reprogramming of the donor nucleus. Cytoplast factors such as maturation promoting factor are implicated based on their involvement in nuclear envelope breakdown (NEBD) and prema

Piezo-assisted nuclear transfer affects cloning efficiency and may cause apoptosis

Even though it generates healthy adults, nuclear transfer in mammals remains an inefficient process. Mainly attributed to abnormal reprograming of the donor chromatin, this inefficiency may also be caused at least partly by a specific effect of the clonin

Impairments in embryonic genome activation in rhesus monkey somatic cell nuclear transfer embryos

Somatic cell nuclear transfer (SCNT) is a remarkable process in which a somatic cell nucleus is acted upon by the ooplasm via mechanisms that today remain unknown. Here we show the developmental competence (% blastocyst) of embryos derived from SCNT (21%)

Re-examination of the phylogeny of Rhacophoridae (Anura) based on mitochondrial and nuclear DNA

The phylogenetic relationships among rhacophorid frogs are under dispute. We use partial sequences of three mitochondrial (12S rRNA, 16S rRNA, and cytochrome b) and three nuclear protein-coding (Rag-1 rhodopsin exon 1, and tyrosinase exon 1) genes from 57

Nuclear matrix of the most primitive eukaryote Archezoa

Accumulating evidence suggests that unicellular Archezoa are the most primitive eukaryotes and their nuclei are of significance to the study of evolution of the eukaryotic nucleus. Nuclear matrix is an ubiquitous important structure of eukaryotic nucleus; its evolution is certainly one of the most important parts of the evolution of nucleus. To study the evolution of nuclear matrix, nuclear matrices of Archezoa are investigated. Giardia lamblia cells are extracted sequentially. Both embedment-free section EM and whole mount cell EM of the extracted cells show that, like higher eukaryotes, this species has a residual nuclear matrix in its nucleus and rich intermediate filaments in its cytoplasm, and the two networks connect with each other to form a united network. But its nuclear matrix does not have nucleolar matrix and its lamina is not as typical as that of higher eukaryotes; Western blotting shows that lamina of Giardia and two other Archezoa Entamoeba invadens and Trichomonas vaginali all contain only one polypeptide each which reacts with a mammalia anti-lamin polyclonal serum and is similar to lamin B (67 ku) of mammlia in molecular weight. According to the results and references, it is suggested that nuclear matrix is an early acquisition of the eukaryotic nucleus, and it and the "eukaryotic chromatin" as a whole must have originated very early in the process of evolution of eukaryotic cell, and their origin should be an important prerequisite of the origin of eukaryotic nucleus; in the iamin (gene) family, B-type lamins (gene) should be the ancestral type and that A-type lamins (gene) might derive therefrom.