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T Qi

Publications and source records attributed to T Qi.

8 recordsLinked to original sources
PubMed2001

Middle Eocene primate tarsals from China: implications for haplorhine evolution.

We describe tarsal remains of primates recovered from the Middle Eocene (approximately 45 mya) Shanghuang fissures in southern Jiangsu Province, China. These tarsals document the existence of four higher-level taxa of haplorhine primates and at least two adapid species. The meager and poorly preserved adapid material exhibits some similarities to European adapines like Adapis. The haplorhine primates are divided into two major groups: a "prosimian group" consisting of Tarsiidae and an unnamed group that is anatomically similar to Omomyidae; and an "anthropoid group" consisting of Eosimiidae and an unnamed group of protoanthropoids. The anthropoid tarsals are morphologically transitional between omomyids (or primitive haplorhines) and extant telanthropoids, providing the first postcranial evidence for primates which bridge the prosimian-anthropoid gap. All of the haplorhines are extremely small (most are between 50-100 g), and the deposits contain the smallest euprimates ever documented. The uniqueness of this fauna is further highlighted by the fact that no modern primate community contains as many tiny primates as does the fauna from Shanghuang.

Animals↗
PubMed2000

The oldest known anthropoid postcranial fossils and the early evolution of higher primates.

The middle Eocene primate family Eosimiidae, which is known from sites in central and eastern China and Myanmar, is central to efforts to reconstruct the origin and early evolution of anthropoid or 'higher' primates (monkeys, apes and humans). Previous knowledge of eosimiid anatomy has been restricted to the dentition and an isolated petrosal bone, and this limited anatomical information has led to conflicting interpretations of early anthropoid phylogeny. Here we describe foot bones of Eosimias from the same middle Eocene sites in China that yield abundant dental remains of this primate. Tarsals of Eosimias show derived anatomical traits that are otherwise restricted to living and fossil anthropoids. These new fossils substantiate the anthropoid status of Eosimias and clarify the phylogenetic position of anthropoids with respect to other major primate clades. Early anthropoids possessed a mosaic of primitive and derived traits in their postcranial skeletons, reflecting their derivation from haplorhine ancestors that retained many prosimian-like features.

Animals↗
PubMed1998

Late eocene sivaladapid primate from Guangxi Zhuang Autonomous Region, People's Republic of China.

A new genus and species of Sivaladapidae is described from the late Eocene Gongkang Formation, Yongle Basin, western Guangxi Zhuang Autonomous Region, southern China. Guangxilemur tongi, new genus and species, shows a combination of traits that occur separately in earlier and more primitive Asian adapiforms (Hoanghonius and Rencunius) and in Miocene sivaladapines (Sivaladapis and Sinoadapis). Phylogenetic analysis of dental characters suggests that Guangxilemur is closely related to the Miocene sivaladapine clade. Miocene sivaladapines were the latest surviving members of a broad radiation of Eocene adapiforms in Asia that included Hoanghonius, Rencunius, and Wailekia in addition to Guangxilemur. European Periconodon may also be specially related to this primarily Asian clade, but current anatomical data are insufficient to test this possibility adequately. Sivaladapine adapiforms and tarsiid tarsiiforms maintained relictual distributions in southern and/or southeastern Asia far beyond the extirpation of their closest relatives on other Holarctic continents near the Eocene-Oligocene boundary. This temporal persistence was mediated by Asian paleogeography, which allowed virtually continuous access to tropical refugia during a middle Cenozoic interval of climatic deterioration that coincided with the extinction of adapiforms and tarsiiforms in Europe and North America.

Animals↗
PubMed1995

[A preliminary study on metastasis-associated gene screened by monoclonal antibodies HIL].

The cDNA expression libraries derived from a highly metastatic cell subline Anip[973] and from the poorly metastatic, parental cell line, AGZY-83a were screened by monoclonal antibodies HIL. A positive clone (H4-D) from the Anip[973] cDNA library was isolated and its nucleotide sequence was determined. This clone contained 978 bp with an open reading frame of 318 bp encoding a polypeptide consisting of 106 amino acids. The H4-D cDNA sequence showed 85% homology with a human propionyl-CoA carboxylase alpha-chain. In western blotting analysis, the MoAb H4 recognized 2 bands (15KD and 27KD) of Anip[973] cell membrane proteins. The mRNA expression of H4-D was higher in Anip[973] cells than in AGZY-83a cells. The metastatic potential of Anip[973] cells was markedly decreased after being pretreated with MoAb H4. The above findings indicate that H4-D has a certain relationship with the metastatic phenotype of Anip[973] cells.

Adenocarcinoma↗
PubMed1990

[Enhancing effect of chuangxinmycin on synthesis of enzymes in tryptophan synthesis pathway of chuangxinmycin-resistant mutant strain of E. coli].

Chuangxinmycin (CXM) and L-trp cause repression of trp-operon in wild strain of E. coli and indolepropanic acid (IPA) causes derepression of this strain. In CXM-resistant mutant strain, CXM and IPA both cause derepression, and interaction of CXM and IPA is competitive. However, L-trp results in neither repression nor derepression in the mutant, but it can counteract the activity of CXM or IPA. These results suggest that there are repression and derepression sites on repressor of E. coli. CXM can bind to both sites, but mainly to repression site. The structure of repression site of the CXM-resistant mutant is altered, so that CXM can not bind to the repression site and binds mainly to the derepression site, thus leading to the derepression of trp-operon.

Anthranilate Synthase↗