Molecular characterization of six Chinese families with m.3460G > A and Leber hereditary optic neuropathy

The primary mutation m.3460G > A occurs with a very low frequency (similar to 1%) in Chinese patients with Leber hereditary optic neuropathy (LHON). Up to now, there is no comprehensive study of Chinese patients harboring this mutation. We characterized six unrelated probands with m.3460G > A in this study, which were identified from 1,626 patients with LHON or suspected with LHON. The overall penetrance of LHON (25.6% [10/39]) in four pedigrees with m.3460G > A was substantially lower than those families with m.11778G > A (33.3% [619/1859]) as reported in our previous study. Intriguingly, family Le688 with a heteroplasmic m.3460G > A presented a lower penetrance (12.5%) than the other three families with a homoplasmic mutation. There is an elevated gender bias (affected male to affected female = 4:1) in the four families with m.3460G > A compared to those LHON families with m.11778G > A (2.4:1). Complete mtDNA sequencing indicated that the six matrilines belonged to haplogroups B4d1, F2, A5b, M12a, D4b2b, and D4b2, respectively. We did not identify any potential secondary mutation(s) that will affect or be associated with the penetrance of LHON in the six probands by using an evolutionary analysis and protein secondary-structure prediction. Taken together, our results suggested that the m.3460G > A mutation occurred multiple times in Chinese LHON patients. The heteroplasmic status of mutation m.3460G > A might influence the penetrance of LHON in family Le688.

The mitochondrial genome organization of the rice frog, Fejervarya limnocharis (Amphibia : Anura): a new gene order in the vertebrate mtDNA

The mitochondrial DNA of the rice frog, Fejervarya limnocharis (Amphibia, Anura), was obtained using long-and-accurate polymerase chain reaction (LA-PCR) combining with subcloning method. The complete nucleotide sequence (17,717 bp) of mitochondrial genome was determined subsequently. This mitochondrial genome is characterized by four distinctive features: the translocation of ND5 gene, a cluster of rearranged tRNA genes (tRNA(Thr), tRNA(Pro), tRNA(Leu) ((CUN))) a tandem duplication of tRNA(Mer) gene, and eight large 89-bp tandem repeats in the control region, as well as three short noncoding regions containing two repeated motifs existing in the gene cluster of ND5/tRNA(Thr)/tRNA(Pro)/tRNA(Leu)/tRNA(Phe). The tandem duplication of gene regions followed by deletions of supernumerary genes can be invoked to explain the shuffling of tRNAM(Met) and a cluster of tRNA and ND5 genes, as observed in this study. Both ND5 gene translocation and tandem duplication of tRNA(Met) were first observed in the vertebrate mitochondrial genomes. (c) 2004 Elsevier B.V. All rights reserved.

Game Vertebrate Densities in Hunted and Nonhunted Forest Sites in Manu National Park, Peru

Manu National Park of southern Peru is one of the most renowned protected areas in the world, yet large-bodied vertebrate surveys conducted to date have been restricted to Cocha Cashu Biological Station, a research station covering <0.06 percent of the 1.7Mha park. Manu Park is occupied by >460 settled Matsigenka Amerindians, 300-400 isolated Matsigenka, and several, little-known groups of isolated hunter-gatherers, yet the impact of these native Amazonians on game vertebrate populations within the park remains poorly understood. On the basis of 1495 km of standardized line-transect censuses, we present density and biomass estimates for 23 mammal, bird, and reptile species for seven lowland and upland forest sites in Manu Park, including Cocha Cashu. We compare these estimates between hunted and nonhunted sites within Manu Park, and with other Neotropical forest sites. Manu Park safeguards some of the most species-rich and highest biomass assemblages of arboreal and terrestrial mammals ever recorded in Neotropical forests, most likely because of its direct Andean influence and high levels of soil fertility. Relative to Barro Colorado Island, seed predators and arboreal folivores in Manu are rare, and generalist frugivores specializing on mature fruit pulp are abundant. The impact of such a qualitative shift in the vertebrate community on the dynamics of plant regeneration, and therefore, on our understanding of tropical plant ecology, must be profound. Despite a number of external threats, Manu Park continues to serve as a baseline against which other Neotropical forests can be gauged.

Genome 10K: A Proposal to Obtain Whole-Genome Sequence for 10 000 Vertebrate Species

The human genome project has been recently complemented by whole-genome assessment sequence of 32 mammals and 24 nonmammalian vertebrate species suitable for comparative genomic analyses. Here we anticipate a precipitous drop in costs and increase in sequ

The complete mitochondrial genome of the Chinese hook snout carp Opsariichthys bidens (Actinopterygii : Cyprinifonnes) and an altemative pattem of mitogenomic evolution in vertebrate

The complete mitochondrial genome sequence of the Chinese hook snout carp, Opsariichthys bidens, was newly determined using the long and accurate polymerase chain reaction method. The 16,611-nucleotide mitogenome contains 13 protein-coding genes, two rRNA genes (12S, 16S) 22 tRNA genes, and a noncoding control region. We use these data and homologous sequence data from multiple other ostariophysan fishes in a phylogenetic evaluation to test hypothesis pertaining to codon usage pattern of O. bidens mitochondrial protein genes as well as to re-examine the ostariophysan phylogeny. The mitochondrial genome of O. bidens reveals an alternative pattern of vertebrate mitochondrial evolution. For the mitochondrial protein genes of O. bidens, the most frequently used codon generally ends with either A or C, with C preferred over A for most fourfold degenerate codon families; the relative synonymous codon usage of G-ending codons is greatly elevated in all categories. The codon usage pattern of O. bidens mitochondrial protein genes is remarkably different from the general pattern found previously in the relatively closely 9 related zebrafish and most other vertebrate mitochondria. Nucleotide bias at third codon positions is the main cause of codon bias in the mitochondrial protein genes of O. bidens, as it is biased particularly in favor of C over A. Bayesian analysis of 12 concatenated mitochondrial protein sequences for O. bidens and 46 other teleostean taxa supports the monophyly of Cypriniformes and Otophysi and results in a robust estimate of the otophysan phylogeny. (C) 2007 Published by Elsevier B.V.

Differential expression of vasa RNA and protein during spermatogenesis and oogenesis in the gibel carp (Carassius auratus gibelio), a bisexually and gynogenetically reproducing vertebrate

The RNA helicase Vasa is a germ cell marker in animals, and its homolog in vertebrates to date has been limited to bisexual reproduction. We cloned and characterized CagVasa, a Vasa homolog from the gibel carp, a fish that reproduces bisexually or gynogenetically. CagVasa possesses 14 RGG repeats and eight conserved motifs of Vasa proteins. In bisexually reproducing gibel carp, vasa is maternally supplied and its zygotic expression is restricted to gonads. By in situ hybridization on testicular sections, vasa is low in spermatogonia, high in primary spermatocytes, reduced in secondary spermatocytes, but disappears in spermatids and sperm. In contrast, vasa persists throughout oogenesis, displaying low-high-low levels from oogonia over vitellogenic oocytes to maturing oocytes. A rabbit anti-Vasa antibody (alpha Vasa) was raised against the N-terminal CagVasa for fluorescent immunohistochemistry. On testicular sections, Vasa is the highest in spermatogonia, reduced in spermatocytes, low in spermatids, and absent in sperm. In the ovary, Vasa is the highest in oogonia but persists throughout oogenesis. Subcellular localization of vasa and its protein changes dynamically during oogenesis. The aVasa stains putative primordial germ cells in gibel carp fry. It detects gonadal germ cells also in several other teleosts. Therefore, Cagvasa encodes a Vasa ortholog that is differentially expressed in the testis and ovary. Interestingly, the alpha Vasa in combination with a nuclear dye can differentiate critical stages of spermatogenesis and oogenesis in fish. The cross-reactivity and the ability to stain stage-specific germ cells make this antibody a useful tool to identify fish germ cell development and differentiation. (c) 2005 Wiley-Liss, Inc.

Amphi-Eomes/Tbr1: An amphioxus cognate of vertebrate Eomesodermin and T-Brain1 genes whose expression reveals evolutionarily distinct domain in amphioxus development

A cDNA for a novel T-box containing gene was isolated from the amphioxus Branchiostoma belcheri. A molecular phylogenetic tree constructed from the deduced amino acid sequence of the isolated cDNA indicates that this gene belongs to the T-Brain subfamily. In situ hybridization reveals that the expression is first detected in the invaginating archenteron at the early gastrula stage and this expression is down-regulated at the neurula stage. In early larvae, the expression appears again and transcripts are detected exclusively in the pre-oral pit (wheel organ-Hatschek's pit of the adult). In contrast to the vertebrate counterparts, no transcripts are detected in the brain vesicle or nerve cord throughout the development. These results are interpreted to mean that a role of T-Brain products in vertebrate forebrain development was acquired after the amphioxus was split from the lineage leading to the vertebrates. On the other hand, comparison of the tissue-specific expression domain of T-Brain genes and other genes between amphioxus and vertebrates revealed that the pre-oral pit of amphioxus has several molecular features which are comparable to those of the vertebrate olfactory and hypophyseal placode. (C) 2002 Wiley-Liss, Inc.

Characterization of amphioxus GDF8/11 gene, an archetype of vertebrate MSTN and GDF11

MSTN, also known as growth and differentiation factor 8 (GDF8), and GDF11 are members of the transforming growth factor-beta (TGF-beta) subfamily. They have been thought to be derived from one ancestral gene. In the present study, we report the isolation and characterization of an invertebrate GDF8/11 homolog from the amphioxus (Branchiostoma belcheri tsingtauense). The amphioxus GDF8/11 gene consists of five exons flanked by four introns, which have two more exons and introns than that of other species. In intron III, a possible transposable element was identified. This suggested that this intron might be derived from transposon. The amphioxus GDF8/11 cDNA encodes a polypeptide of 419 amino acid residues. Phologenetic analysis shows that the GDF8/11 is at the base of vertebrate MSTNs and GDF11s. This result might prove that the GDF8/11 derived from one ancestral gene and the amphioxus GDF8/11 may be the common ancestral gene, and also the gene duplication event generating MSTN and GDF11 occurred before the divergence of vertebrates and after or at the divergence of amphioxus from vertebrates. Reverse transcriptase polymerase chain reaction results showed that the GDF8/11 gene was expressed in new fertilized cell, early gastrulation, and knife-shaped embryo, which was different from that in mammals. It suggested that the GDF8/11 gene might possess additional functions other than regulating muscle growth in amphioxus.

辽东栎天然更新

在北京东灵山地区对辽东栎的天然更新进行研究。辽东栎的结实具有大年现象（masting），大年现象十分复杂，在种群水平、个体之间都存在差异。 动物对辽东栎的天然更新有重要的影响。捕食和传播辽东栎坚果的脊椎动物至少包括小型啮齿目动物中的岩松鼠、花鼠、大仓鼠、社鼠、大林姬鼠和棕背鼠平，鸟类中的松鸦。岩松鼠、花鼠和大仓鼠有发达的颊囊，能够将坚果暂时放在颊囊中进行传播，岩松鼠有分散埋藏坚果的习性;松鸦能够将坚果放在素囊中进行长距离传播。成熟坚果在森林地表的消失非常快，少部分被脊椎动物就地消耗，大部分被传播到巢穴中或分散埋藏。成熟坚果的丢失存在时空差异。无脊椎动物中的昆虫对辽东栎去叶有重要影响。去叶与昆虫幼虫的密度以及长度显著相关。幼树去叶在辽东栎种群大树密度最高的地点最高，而在密度最低的地点最低。大树去叶在辽东栎种群总胸径面积最大的地点最大。 辽东栎实生苗在野外十分匮乏，可能是由于东灵山地区小型啮齿目动物缺乏天敌，使它们的活动十分强烈。它们有异常强大的捕食和搬运辽东栎坚果的能力，使能够逃逸捕食的坚果数量很少。现阶段辽东栎的更新几乎完全靠萌生苗进行，大树的生长大多弯曲不直。实生幼苗在小的林窗中的生长比在树冠下的生长好。综合考虑实生个体和萌生个体，50 龄林中种群大小结构稳定，能够长时间生存发展下去;30 龄林种群中个体间的竞争激烈，种群处于衰退状态。 研究结果建议：对辽东栎林的天然更新，应该采取综合治理的方法，充分考虑各种生物和非生物因素的影响，处理好生物因素的非生物因素的关系;人为进行适当干扰，例如在森林中创建适当大小的林窗，以更好地促进辽东栎的天然更新。