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Revista de filogenética y biología evolutiva

Volumen 2, Asunto 1 (2014)

Artículo de investigación

Study of Conserved Domain across Divergent Phylogenetic Lineages of Long Neurotoxin from Genus Naja (Elapidae Family)

Sherkhane AS , Waghmare Somnath and Gomase VS

Naja are a toxic genus of Elapids family in the old world. Long neurotoxins are mixtures of peptides, enzymes that interfere with the normal function of the nervous system and potently block α7 homo-oligomeric neuronal AChRs causing paralysis. The aim of the present study is to identify the origin of long neurotoxin, multiple sequences analysis for prediction of structure and function of neurotoxin and observing the conserved pattern of amino acid residues and to construct the phylogenetic tree for organizing evolutionary history of Naja genus from Elapidae family.

Artículo de revisión

Genes and Genome of HIV-1

Rajarapu G

There are currently various different tests for HIV infections such as HIV antibody test, P24 antigen test, Polymerase chain reaction test (PCR), Fourth generation test and Home test. Even though there is no particular treatment or therapy for HIV, very effective treatment called antiviral therapy, combination therapy, or HAART (highly active antiretroviral therapy) can retain the virus under control and permit someone with HIV to have an active, health life. Some people have acquired the side effects from their medications, such as nausea, diarrhoea, prolonged headaches, depression and mental health problems. Emergency anti-HIV medication (PEP) may stop people becoming infected, but treatment must be started within three days of coming into contact with the virus. HIV symptoms have not appeared in many of the people. Blood test is the only way to find HIV infection. We can reduce the HIV infection by using a condom during sex and reducing the number of partners. HIV regulatory, accessory proteins and envelope proteins are play a major role in vaccine development. Anti-HIV vaccines have required generating neutralizing antibodies (NAbs) and effective T-cell responses. Recently FDA has approved the one vaccine SAV001 for human clinical trial that is very important milestone for vaccine development. This vaccine has the potential to save the lives of people by preventing HIV infection.

Artículo de investigación

Histological and Scanning Electron Microscopic Examination of the Digestive Tract in Whitespotted Conger, Conger Myriaster (Anguilliformes)

Shunpei Takiue and Hideo Akiyoshi

The morphology of the digestive tract of Whitespotted conger, Conger myriaster (Elopomorpha: Anguilliformes) was examined by light and scanning electron microscopy. The digestive tracts consist of esophagus, stomach, and intestine; no pyloric caeca were observed. The stomach was divided into cardiac, body, terminal and pyloric region. The esophagus was composed of two layers of striated muscularis; inner longitudinal layer and outer circular layer. The former was extended to the body region of the stomach. In contrast, the latter was terminated to the esophagus, and became coincident to the boundary of the outer longitudinal layer consisting of smooth muscle in the cardiac region of the stomach. The terminal region of the stomach was characterized by the thick longitudinal muscularis and subserosa, and the gastric glands were absent. Ciliated cells were distributed in the intestinal wall. The digestive tract secreted both acidic and neutral mucus throughout all regions. We found that the terminal region of the stomach is characteristic of Anguilliformes. On the other hand, the striated muscle within the body region of the stomach was unique among the Anguilliformes. These differences in stomach suggested the possible existence of morphological differences that originate from phylogenetic position among the orders in Elopomorpha.

Artículo de investigación

Development and Maintenance of a Cross-mixed Mating System in the Orchid Bulbophyllum orientale

Li-Jun Chen, Guo-Qiang Zhang, Li-Qiang Li, Yu-Ting Zhang, Wen-Hui Rao and Zhong-Jian Liu

Outbreeding is usually advantageous because inbreeding suffers from depression. Nevertheless, mixed mating is very common in nature. We found two co-existing plant types, self-compatible and self-incompatible, in populations of the orchid Bulbophyllum orientale. The floral parts of this plant form a device to promote cross-pollination. Rancid substances are excreted to lure pollinators to the labellum, and pollens are attached to pollinators through a delicate mechanism. Given that many inflorescences and flowers are present on a clone and each inflorescence, respectively, pollinating insects may continuously visit inflorescences of the same clone and flowers of the same inflorescence but rarely continuously visit different populations separated by large distances. Consequently, self-compatible plants produce seeds from both crossing and selfing, and self-incompatible plants only bear crossing seeds. Thus, a crossmixed mating system is created in the population. Individuals capable of producing both crossed and selfed seeds have better chances in natural selection. The strict crossing system is broken down, and a cross-mixed mating system consisting of both mixed mating and strict crossing is formed. The cross-mixed mating system fluctuates with varying behavior of pollinating insects. The mixed mating system is favored because a population has many clone individuals and because each individual has many multi-flower inflorescences in B. orientale. The partial strict crossing is retained, and it can counteract the latent harm caused by selfing and assist in the maintenance of this cross-mixed mating system. The successful evolution of flowering plants is demonstrated by the mode of attraction for pollinating insects, the smart use of the cross-pollinating facility, and the tradeoff between crossing and mixed mating.

Editorial

Some Current Concerns of Neo-Darwinism:Gene Introgression Throughout a Species Border

Yuri Ph. Kartavtsev

The author introduces the notion of hybrid and occurrence of hybridization estimates by means of molecular markers. In this editorial evidence on possible impact of gene introgression on species integrity, its evolutionary fate and consistence with main modern paradigm, Neo-Darwinism are considered.

Artículo de investigación

Monitoring Climate Change Impact on the Genetic Population Structure: The Case of the Fivebeard Rockling (Ciliata Mustela, Linnaeus, 1758) In Its Southern Limit of Distribution

Joana I Robalo, Cristina S Lima, Sara M Francisco, Frederico Almada, Rafael Banõn, David Villegas-Ríos and Vítor C Almada

Ciliata mustela is a marine inshore fish which occurs from central Portugal to northeastern Norway. We studied the population structure of this species using cytochrome b gene and the first intron of the nuclear S7 ribosomal protein gene and samples ranging from central Portugal to Gullmars Fjord, Sweden. We tested the following alternative hypotheses: 1) is the Portuguese population of the fivebeard rockling self-sustainable? or 2) is this population dependent on migrants from the north? We found no detectable subdivision among locations. Genetic diversity indices did not change along the study area. The data support persistence during one or several glacial cycles and a rapid expansion about 10 thousand years ago. In Portugal the populations of this species are strongly affected by climatic oscillations with severe reductions in warm years (bellow detection) and recoveries in cold years. We found that the percentage of private haplotypes is consistently lower in Portugal than in other locations. Our results support the hypothesis that the Portuguese population is mainly dependent on migrants from northern locations. We discuss the possibility of using species as C. mustella to monitor short term effects on the genetic structure of populations and their relation with climate change.

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