Establishing a laboratory colony of the Japanese lancelet (amphioxus)

Despite an intelest of long standing in the origin and evolution of vertebrates,recent contribution of studies on lancelets(amphioxus),cephalochordates,to this field is not much.One of the major reasons for this is difficulties in applying effective molecular techniques to this animal.To estabhsh a base of easy-use of lancelet materials,we are improving a laboratorγ culture system of lancelets and have obtained sufficient spawns for six years.We also performed stocking with about 14,000 young lancelets at the native habitat in the Ariake Sea,Japan.With embryos obtained from the culture system,we first transformed epidermal cells of late neurulae with EGFP expression vectors by electroporation method.Our culture System is is releaslng lancelet studies from constraint

The Hox8 of the hemichordate Balanoglossus misakiensis

金沢大学理工研究域自然システム学系Deuterostomes comprise a monophyletic group of animals that include chordates, xenoturbellids, and the Ambulacraria, which consists of echinoderms and hemichordates. The ancestral chordate probably had 14 Hox genes aligned linearly along the chromosome, with the posterior six genes showing an independent duplication compared to protostomes. In contrast, ambulacrarians are characterized by a duplication of the posterior Hox genes, resulting in three genes known as Hox11/13a, Hox11/ 13b, and Hox11/13c. Here, we isolated 12 Hox genes from the hemichordate Balanoglossus misakiensis and found an extra Hox gene that has not been reported in hemichordates. The extra B. misakiensis gene was suggested to be Hox8 from paralog-characteristic residues in its hexapepetide motif and homeodomain and a comparison with Strongylocentrotus purpuratus Hox genes. Our data suggest that the ancestor of echinoderms and hemichordates may have had a full complement of 12 Hox genes. © Springer-Verlag 2009

Tiny Sea Anemone from the Lower Cambrian of China

Background Abundant fossils from the Ediacaran and Cambrian showing cnidarian grade grossly suggest that cnidarian diversification occurred earlier than that of other eumetazoans. However, fossils of possible soft-bodied polyps are scanty and modern corals are dated back only to the Middle Triassic, although molecular phylogenetic results support the idea that anthozoans represent the first major branch of the Cnidaria. Because of difficulties in taxonomic assignments owing to imperfect preservation of fossil cnidarian candidates, little is known about forms ancestral to those of living groups. Methods and Findings We have analyzed the soft-bodied polypoid microfossils Eolympia pediculata gen. et sp. nov. from the lowest Cambrian Kuanchuanpu Formation in southern China by scanning electron microscopy and computer-aided microtomography after isolating fossils from sedimentary rocks by acetic acid maceration. The fossils, about a half mm in body size, are preserved with 18 mesenteries including directives bilaterally arranged, 18 tentacles and a stalk-like pedicle. The pedicle suggests a sexual life cycle, while asexual reproduction by transverse fission also is inferred by circumferential grooves on the body column. Conclusions The features found in the present fossils fall within the morphological spectrum of modern Hexacorallia excluding Ceriantharia, and thus Eolympia pediculata could be a stem member for this group. The fossils also demonstrate that basic features characterizing modern hexacorallians such as bilateral symmetry and the reproductive system have deep roots in the Early Cambrian.Funding was provided by the National Science Foundation of China (http://www.nsfc.gov.cn/) grants 40830208, 40602003, 50702005 to J. Han and D. G. Shu, and by MOST Special Fund from the State Key Laboratory of Continental Dynamics, Northwest University, China (http://sklcd.nwu.edu.cn/) to J. Han and D. G. Shu. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewe

Skeletal Observation of a Wild Chimpanzee Infant (Pan troglodytes schweinfurthii) from the Mahale Mountains, Tanzania

A wild female chimpanzee infant whose date of birth and death were roughly documented died in the Mahale Mountains, Tanzania. Observation and measurements of its skeletal remains and dental investigation by radiograph were carried out. The results of the measurements and the condition of cranial sutures coincide with those of previous studies, but the calcification of the crowns of P3 and P4 have already started by 1.8-1.9 months of age. These calcifications are slightly earlier than previous records have stated. These data serve to correct the data obtained from specimens in captivity or in the wild whose exact ages are not known

Excavation at the Fossil-Hominoid-Bearing Locality, Site-SH22 in the Samburu Hills, Northern Kenya

An excavation has been carried out at the SH22 locality where a fossil of a large hominoid (KNM-SH-8531) was found in 1982. This site is located in the Samburu Hills, northern Kenya and dated back to upper Miocene. During the 1984 field season, a large number of new fossils were recovered at this locality. These fossils and sedimentological analysis revealed that the fossil bed at the SH22 locality may be a marginal deposit of an abandoned channel on a dried lake floor

Additional Large Mammalian Fauna from the Namurungule Formation, Samburu Hills, Northern Kenya

Some 1150 late Miocene vertebrate fossils were collected by the Japan-Kenya Expedition from the Namurungule Formation in the Samburu Hills, Northern Kenya. The Namurungule mammalian local fauna has simillarities to late Miocene Eurasian faunas from Samos and Pikermi (Greece), Maragheh (Iran), and the Nagri and Dhok Pathan Formations of the Siwalik Hills (India). This similarity indicates mammalian interchanges between Eurasian and Africa during the late Miocene. The svanna fauna of the Namurungule Formation differs completely from the earilier Aka Aiteputh Formation fauna, which indicates a woodland enviroment (Pickford et al. 1984). This great change in the mammalian fauna of the East African late Miocene coincided with the beginning of the opening of the Gregory Rift