Cranial morphological features of the stem-group sarcopterygian Guiyu oneiros Zhu et al.,2009 provided here include the dermal bone pattern and anatomical details of the ethmosphenoid.Based on those features,we restor...Cranial morphological features of the stem-group sarcopterygian Guiyu oneiros Zhu et al.,2009 provided here include the dermal bone pattern and anatomical details of the ethmosphenoid.Based on those features,we restored,for the first time,the skull roof bone pattern in the Guiyu clade that comprises Psarolepis and Achoania.Comparisons with Onychodus,Achoania,coelacanths,and actinopterygians show that the posterior nostril enclosed by the preorbital or the preorbital process is shared by actinopterygians and sarcopterygians,and the lachrymals in sarcopterygians and actinopterygians are not homologous.The endocranium closely resembles that of Psarolepis,Achoania and Onychodus;however,the attachment area of the vomer possesses irregular ridges and grooves as in Youngolepis and Diabolepis.The orbito-nasal canal is positioned mesial to the nasal capsule as in Youngolepis and porolepiforms.The position of the hypophysial canal at the same level or slightly anterior to the ethmoid articulation represents a synapmorphy of the Guiyu clade.The large attachment area of the basicranial muscle indicates the presence of a well-developed intracranial joint in Guiyu.展开更多
Sarcopterygians is an important vertebrate clade that includes crossopterygians and tetrapods.Crossopterygians are lobe-finned fish that include lungfish and coelacanths.Tetrapods include amphibians,reptiles,avians an...Sarcopterygians is an important vertebrate clade that includes crossopterygians and tetrapods.Crossopterygians are lobe-finned fish that include lungfish and coelacanths.Tetrapods include amphibians,reptiles,avians and mammals.To compare the interferon regulatory factor 1 (irf-1) gene structure and to explore phylogenetic relationships among sarcopterygians,we cloned the cDNA sequence of irf-1 from lungfish and compared it with irf-1 orthologs in other sarcopterygian species.The lungfish is a primitive sarcopterygian that occupies a very important position in vertebrate phylogeny.Interferon regulatory factors (IRFs) are a family of proteins involved in innate immunity.To date,11 IRF family members have been reported.All IRFs share homology in the first 115 amino acids,which encompasses a DNA binding domain containing a characteristic repeat of 5 tryptophan residues separated by 10-18 amino acids.IRF-1 and IRF-2 were the first members of this family to be reported and they have a very important role in innate immunity.However,studies of the irf-1 and irf-2 genes are mostly confined to mammals;very few non-mammalian irf-1 genes have been reported.Consistent with the irf-1 gene sequences already published,the first 345 nucleotides of lungfish irf-1 are highly conserved.At the carboxyl terminal a C-terminal transactivating region motif and an interferon associated domain (IAD2) were identified.417 million years separate the present from the closest common ancestor of lungfish and tetrapods;however,the irf-1 genes among sarcopterygians are highly conserved and have very obvious phylogenetic relationships.Also the interrelationship tree of sarcopterygians,based on IRF-1 amino acid sequences,is identical with trees produced using other data,such as morphological characteristics or mitochondrial gene sequences.展开更多
基金supported by National Basic Research Program of China (Grant No. 2006CB806400)Knowledge Innovation Program of the Chinese Academy of Sciences (Grant No. KZCX2-YW-156)+1 种基金National Natural Science Foundation of China (Grant No. 40930208)the CAS/SAFEA International Partnership Program for Creative Research Teams
文摘Cranial morphological features of the stem-group sarcopterygian Guiyu oneiros Zhu et al.,2009 provided here include the dermal bone pattern and anatomical details of the ethmosphenoid.Based on those features,we restored,for the first time,the skull roof bone pattern in the Guiyu clade that comprises Psarolepis and Achoania.Comparisons with Onychodus,Achoania,coelacanths,and actinopterygians show that the posterior nostril enclosed by the preorbital or the preorbital process is shared by actinopterygians and sarcopterygians,and the lachrymals in sarcopterygians and actinopterygians are not homologous.The endocranium closely resembles that of Psarolepis,Achoania and Onychodus;however,the attachment area of the vomer possesses irregular ridges and grooves as in Youngolepis and Diabolepis.The orbito-nasal canal is positioned mesial to the nasal capsule as in Youngolepis and porolepiforms.The position of the hypophysial canal at the same level or slightly anterior to the ethmoid articulation represents a synapmorphy of the Guiyu clade.The large attachment area of the basicranial muscle indicates the presence of a well-developed intracranial joint in Guiyu.
基金supported by the National Key Basic Research Program of China (HCV2009CB522500)
文摘Sarcopterygians is an important vertebrate clade that includes crossopterygians and tetrapods.Crossopterygians are lobe-finned fish that include lungfish and coelacanths.Tetrapods include amphibians,reptiles,avians and mammals.To compare the interferon regulatory factor 1 (irf-1) gene structure and to explore phylogenetic relationships among sarcopterygians,we cloned the cDNA sequence of irf-1 from lungfish and compared it with irf-1 orthologs in other sarcopterygian species.The lungfish is a primitive sarcopterygian that occupies a very important position in vertebrate phylogeny.Interferon regulatory factors (IRFs) are a family of proteins involved in innate immunity.To date,11 IRF family members have been reported.All IRFs share homology in the first 115 amino acids,which encompasses a DNA binding domain containing a characteristic repeat of 5 tryptophan residues separated by 10-18 amino acids.IRF-1 and IRF-2 were the first members of this family to be reported and they have a very important role in innate immunity.However,studies of the irf-1 and irf-2 genes are mostly confined to mammals;very few non-mammalian irf-1 genes have been reported.Consistent with the irf-1 gene sequences already published,the first 345 nucleotides of lungfish irf-1 are highly conserved.At the carboxyl terminal a C-terminal transactivating region motif and an interferon associated domain (IAD2) were identified.417 million years separate the present from the closest common ancestor of lungfish and tetrapods;however,the irf-1 genes among sarcopterygians are highly conserved and have very obvious phylogenetic relationships.Also the interrelationship tree of sarcopterygians,based on IRF-1 amino acid sequences,is identical with trees produced using other data,such as morphological characteristics or mitochondrial gene sequences.
