Fourteen species of nonmarine gastropod opercula are found to be in high abundance in the Oligocene upper member of the Yehucheng Formation,Lanzhou Basin,northwest China.They are attributed to two families,namely Bith...Fourteen species of nonmarine gastropod opercula are found to be in high abundance in the Oligocene upper member of the Yehucheng Formation,Lanzhou Basin,northwest China.They are attributed to two families,namely Bithyniidae and Assimineidae,and four genera,namely Pseudemmericia,Bithynia,Mirolaminatus and Assiminea.Among them,three species are new,and they are Bithynia paramonolithic sp.nov.,B.obliquus sp.nov.,and B.disregularis sp.nov.Some of these species were first discovered in Paleogene strata of the vast Northwest China and can be compared with the opercula recovered from the Paleogene deposits in East and South China.It is inferred from the paleontology and sediment associations that the climate was slightly humid and the fauna probably inhabited the fresh or brackish water of a shallow lake in the Lanzhou Basin during the late early Oligocene period.展开更多
Age of African pike Hepsetus odoe from Ado Ekiti Reservoir Ekiti State, Nigeria was studied. Annuli on the opercula bones and scales were used to determine the age. The standard length of specimens examined varied bet...Age of African pike Hepsetus odoe from Ado Ekiti Reservoir Ekiti State, Nigeria was studied. Annuli on the opercula bones and scales were used to determine the age. The standard length of specimens examined varied between 12.50 and 29.80 cm and body weight 10-385 g. Annuli （growth rings） observed on the opercula bones of specimens with mean standard lengths 21.70 ± 1.4 cm had one real annulus, 24.80 ± 1.1 cm had two real annuli, 27.4 ± 0.9 cm had three real annuli indicating age one, two, and three （1 ＋, 2＋, 3＋ ） respectively. Growth rings observed on scales appeared as interruptions in the normal pattems of scales. Specimens with mean standard lengths of 21.3 ± 1.5 cm, 24.7 ± 0.8 cm and 27.35 ± 11 cm were interpreted to be ages 1＋, 2＋, and 3＋ respectively. The maximum age of samples, derived from annuli on both opercula bones and scales was 3 years. Specimens below 18 cm standard length did not register any growth mark. The mean lengths at the estimated ages obtained using both opercula bones and scales were not significantly different （P 〉 0.05, P 〉 0.01）.展开更多
Population dynamics of the Balanus improvises （Crustacean： Cirripedia） was studied in three stations Amirabad, Khazarabad in the eastern part and Noor in the central part of the Southern Coasts of the Caspian Sea. ...Population dynamics of the Balanus improvises （Crustacean： Cirripedia） was studied in three stations Amirabad, Khazarabad in the eastern part and Noor in the central part of the Southern Coasts of the Caspian Sea. Sampling procedure was carried out monthly from July 2007 to July 2008. In this study longitudinal diameter aperture （orifice or opercula diameter） of4118 individuals as well as dry weight and ash free dry weight of 141 barnacles were measured. Barnacle population density decreased in all three stations during autumn and winter. Barnacle density in Khazarabad were significantly higher than the other two stations （P 〉 0/05）. In this study, for dry weight and ash free dry weight maximum 247 and 122 mg and minimum 0/5 and 0/25 mg were obtained respectively. Emergence of a young cohort in March 2008, indicates the reproduction season and larval recruitment at this time. Also the frequency of the larval recruitment from April 2004 until mid-summer had increased. Opercula diameter of B. improvisus correlated with dry weight （R2 = 0/87, n = 115） and ash free dry weight （R2= 0/77, n = 115）. In addition, two equations for correlation of opercula diameter with dry weight （W = 0/49 L2/6, Re= 14） and ash free dry weight （W = 0/16 L2/81, Re = 18/8） for this species were calculated.展开更多
Sp7/Osterix as a zinc finger transcription factor is expressed specifically in osteoblasts. Embryonic lethality of Sp7 knockout mice, however, has prevented from examining the functions of Sp7 in osteoblast and bone f...Sp7/Osterix as a zinc finger transcription factor is expressed specifically in osteoblasts. Embryonic lethality of Sp7 knockout mice, however, has prevented from examining the functions of Sp7 in osteoblast and bone formation in live animals. Here we used TALEN, a versatile genome-editing tool, to generate one zebrafish sp7 mutant line. Homozygous sp7-/- mutant zebrafish are able to survive to adulthood. Alizarin Red staining and Micro-CT analysis showed that sp7-/- larvae and adult fish fail to develop normal opercula, and display curved tail fins and severe craniofacial malformation, while Alcian Blue staining showed no obvious cartilage defects in sp7-/- fish. Quantitative RT-PCR showed that a number of osteoblast markers including sppl, phex, collala, and collalb are significantly down-regulated in sp7-/- fish. Furthermore, col10a1a, whose ortholog is the cartilage marker in mice, was shown to be a novel downstream gene of Sp7 as an osteoblast marker in zebrafish. Together, these results suggest that Sp7 is required for zebrafish bone development and zebrafish sp7 mutants provide animal models for investigating novel aspects of bone development.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.42172010)。
文摘Fourteen species of nonmarine gastropod opercula are found to be in high abundance in the Oligocene upper member of the Yehucheng Formation,Lanzhou Basin,northwest China.They are attributed to two families,namely Bithyniidae and Assimineidae,and four genera,namely Pseudemmericia,Bithynia,Mirolaminatus and Assiminea.Among them,three species are new,and they are Bithynia paramonolithic sp.nov.,B.obliquus sp.nov.,and B.disregularis sp.nov.Some of these species were first discovered in Paleogene strata of the vast Northwest China and can be compared with the opercula recovered from the Paleogene deposits in East and South China.It is inferred from the paleontology and sediment associations that the climate was slightly humid and the fauna probably inhabited the fresh or brackish water of a shallow lake in the Lanzhou Basin during the late early Oligocene period.
文摘Age of African pike Hepsetus odoe from Ado Ekiti Reservoir Ekiti State, Nigeria was studied. Annuli on the opercula bones and scales were used to determine the age. The standard length of specimens examined varied between 12.50 and 29.80 cm and body weight 10-385 g. Annuli （growth rings） observed on the opercula bones of specimens with mean standard lengths 21.70 ± 1.4 cm had one real annulus, 24.80 ± 1.1 cm had two real annuli, 27.4 ± 0.9 cm had three real annuli indicating age one, two, and three （1 ＋, 2＋, 3＋ ） respectively. Growth rings observed on scales appeared as interruptions in the normal pattems of scales. Specimens with mean standard lengths of 21.3 ± 1.5 cm, 24.7 ± 0.8 cm and 27.35 ± 11 cm were interpreted to be ages 1＋, 2＋, and 3＋ respectively. The maximum age of samples, derived from annuli on both opercula bones and scales was 3 years. Specimens below 18 cm standard length did not register any growth mark. The mean lengths at the estimated ages obtained using both opercula bones and scales were not significantly different （P 〉 0.05, P 〉 0.01）.
文摘Population dynamics of the Balanus improvises （Crustacean： Cirripedia） was studied in three stations Amirabad, Khazarabad in the eastern part and Noor in the central part of the Southern Coasts of the Caspian Sea. Sampling procedure was carried out monthly from July 2007 to July 2008. In this study longitudinal diameter aperture （orifice or opercula diameter） of4118 individuals as well as dry weight and ash free dry weight of 141 barnacles were measured. Barnacle population density decreased in all three stations during autumn and winter. Barnacle density in Khazarabad were significantly higher than the other two stations （P 〉 0/05）. In this study, for dry weight and ash free dry weight maximum 247 and 122 mg and minimum 0/5 and 0/25 mg were obtained respectively. Emergence of a young cohort in March 2008, indicates the reproduction season and larval recruitment at this time. Also the frequency of the larval recruitment from April 2004 until mid-summer had increased. Opercula diameter of B. improvisus correlated with dry weight （R2 = 0/87, n = 115） and ash free dry weight （R2= 0/77, n = 115）. In addition, two equations for correlation of opercula diameter with dry weight （W = 0/49 L2/6, Re= 14） and ash free dry weight （W = 0/16 L2/81, Re = 18/8） for this species were calculated.
基金supported by the grants from National High Technology Research and Development Program of China (2011AA100402-2)the National Natural Science Foundation of China (NSFC) (31271356, 31030062, 81070455)+5 种基金National Basic Research Program of China (2012CB947600)the Jiangsu Distinguished Professorship Program (SR13400111)the Natural Science Foundation of Jiangsu Province (BK2012052)the Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions (YX13400214)the High-Level Innovative Team of Jiangsu Provincethe ‘‘333” project of Jiangsu Province (BRA2015328)
文摘Sp7/Osterix as a zinc finger transcription factor is expressed specifically in osteoblasts. Embryonic lethality of Sp7 knockout mice, however, has prevented from examining the functions of Sp7 in osteoblast and bone formation in live animals. Here we used TALEN, a versatile genome-editing tool, to generate one zebrafish sp7 mutant line. Homozygous sp7-/- mutant zebrafish are able to survive to adulthood. Alizarin Red staining and Micro-CT analysis showed that sp7-/- larvae and adult fish fail to develop normal opercula, and display curved tail fins and severe craniofacial malformation, while Alcian Blue staining showed no obvious cartilage defects in sp7-/- fish. Quantitative RT-PCR showed that a number of osteoblast markers including sppl, phex, collala, and collalb are significantly down-regulated in sp7-/- fish. Furthermore, col10a1a, whose ortholog is the cartilage marker in mice, was shown to be a novel downstream gene of Sp7 as an osteoblast marker in zebrafish. Together, these results suggest that Sp7 is required for zebrafish bone development and zebrafish sp7 mutants provide animal models for investigating novel aspects of bone development.
