Parvibellus atavus gen. et sp. nov. from the Early Cambrian Chengjiang fauna of China is a small fossil having distinct cephalic region bearing pair lateral projections and circular, ventral mouth. The trunk bears eleven pairs probably flap-like appendages short terminal projections. This character combination unique for biota. A circular mouth seen in Radiodonta some gilled lobopodians which a...

During S phase, not only does DNA have to be replicated, but also newly synthesized DNA molecules have to be connected with each other. This sister chromatid cohesion is essential for the biorientation of chromosomes on the mitotic or meiotic spindle, and is thus an essential prerequisite for chromosome segregation. Cohesion is mediated by cohesin complexes that are thought to embrace sister ch...

BACKGROUND Homologous chromosomes separate in meiosis I and sister chromatids separate in meiosis II, generating haploid gametes. To address the question why sister chromatids do not separate in meiosis I, we explored the roles of Shogoshin1 (Sgo1) in chromosome separation during oocyte meiosis. METHODOLOGY/PRINCIPAL FINDINGS Sgo1 function was evaluated by exogenous overexpression to enhance ...

Kinetochores of sister chromatids attach to microtubules emanating from the same pole (coorientation) during meiosis I and microtubules emanating from opposite poles (biorientation) during meiosis II. We find that the Aurora B kinase Ipl1 regulates kinetochore-microtubule attachment during both meiotic divisions and that a complex known as the monopolin complex ensures that the protein kinase c...

background: alkaptonuria (aku) or ochronosis is a rare progressive degenerative arthropathy that results from deficiency of enzyme homogentisate 1,2 dioxygenase (hgd). the features include arthritis of the spine and in larger peripheral joints, with chondrocalcinosis. in this paper, we present a case of alkaptonuria in a 54 year old woman in tehran, iran. case presentation: a 54 year old woman ...

traditionally, capoeta populations from the southern caspian sea basin have been considered as capoeta capoeta gracilis. study on the phylogenetic relationship of capoeta species using mitochondrial cytochrome b gene sequences show that capoeta population from the southern caspian sea basin is distinct species and receive well support (posterior probability of 100%). based on the tree topologie...

spastic paraplegia 18 is an autosomal recessive disorder characterized by motor dysfunction, joint contracture and mental retardation. we describe two families as three cases. case 1 is a 35-year-old woman with and spasticity and mild weakness in lower limbs. case 2 and 3 are a sister and brother aged six and two respectively. the older sister suffered from lower limb spasticity, equinovarus an...

hodbat-ibn-khashram was from ozreh tribe. information about him and his poetry can be rarely found in sources. the only findings are about his arguments with his cousin ziyadat. ibn khashram was the one who had started this struggle which caused him to kill ziyadat. for this reason, their tribes fought each other as well and finally he was hanged. in their struggle, at first, ziyadat cursed at ...

background: more than 60 species of the genus lathyrus are distributed in southwest asia. it is the second largest genus of the tribe fabeae, after vicia, in the region (and in iran with 23 species). in the regional flora (flora of turkey, florairanicaand flora of iran), the genus has been divided into 9-10 sections. here we analyzed the phylogeny of lathyrus and its relationship with pisum bas...

During mitosis in vertebrate somatic cells, the single attached kinetochore on a mono-oriented chromosome exhibits directional instability: abruptly and independently switching between constant velocity poleward and away from the pole motility states. When the non-attached sister becomes attached to the spindle (chromosome bi-orientation), the motility of the sister kinetochores becomes highly ...