Search Results - (Author, Cooperation:M. Babic)

2015-08-22

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Animals ; Cell Line, Tumor ; Cell Membrane/metabolism/*physiology ; Cricetinae ; Drosophila melanogaster ; Fibroblasts ; *Membrane Potentials ; Mice ; Neurons ; Phosphatidylinositol 4,5-Diphosphate/*metabolism ; Phosphatidylserines/*metabolism ; Signal Transduction ; ras Proteins/*metabolism

1365-3083

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

The jawless Agnatha (lampreys and hagfishes) represent the phylogenetically oldest order of vertebrates that are believed to lack the adaptive immune system of jawed vertebrates. In order to search for molecular markers specific for cellular components of the adaptive immune system in lampreys, we used the polymerase chain reaction (PCR) to identify genes for transcription factors of the Ikaros family in genomic DNA and cDNA libraries from two species of lampreys, Petromyzon marinus and Lampetra fluviatilis. The mammalian Ikaros-like family of transcription factors consists of five members, Ikaros, Helios, Aiolos, Eos and Pegasus, of which the first three appear to be essential for lymphocyte development. Two different Ikaros-like genes, named IKLF1 and IKLF2, were identified in lamprey. They both have the conserved exon–intron structure of seven exons and show alternative splicing like their counterparts in jawed vertebrates. The genes code for predicted proteins of 589 and 513 amino acid residues, respectively. The proteins contain six highly conserved zinc finger motifs that are 83–91% identical to the mammalian members of the Ikaros-like family. The remaining parts of the sequences are, however, mostly unalignable. Phylogenetic analysis based on the alignable segments of the sequences does not identify the orthologous gene in jawed vertebrates but rather shows equidistance of the lamprey Ikaros-like factors to each other and to Ikaros, Helios, Aiolos and Eos. Expression studies by reverse transcription (RT)–PCR and in situ hybridization (ISH), however, provide evidence for moderate expression in presumed lymphoid tissues like the gut epithelium and for high levels of expression in the gonads, especially in the ovary.

Electronic Resource

0922-3371

Basal lamina ; Bursa pharyngea ; Cell contact ; Endoderm ; Human embryo ; Notochord

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Electronic Resource

0300-9084

activite des phophatases de la caseine ; casein phosphatase activity ; erythocytes ; erythrocytes ; ontogenese ; ontogenesis ; phosphatases proteiques ; protein phosphatase

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Electronic Resource

1432-0533

Key words Human spinal cord ; Neurulation ; Dysraphism

Springer Online Journal Archives 1860-2000

Medicine

Abstract Differences in histological appearance between the cranial and caudal parts of the spinal cord and associated axial organs were analyzed in 9- and 15-week-old human dysraphic fetuses and compared with normal fetuses. In human development the cranial part of the neural tube down to the lumbosacral level forms during primary neurulation, while its caudal part results from secondary neurulation. In the 9-week fetus with cervical spina bifida, the cranial spinal cord displayed a variety of morphological changes along the cranio-caudal axis. Spinal cord in the upper cervical region transformed into the area cerebrovasculosa, while the lower cervical and thoracic levels showed only disturbed differentiation of the cell layers and roof plate. The degree of the cranial spinal cord dysmorphogenesis correlated with anomalies of the underlying notochord and vertebral column. The caudal to lumbosacral region of the spinal cord appeared normal. In the case of the 15-week-old fetus with complete dysraphia, the area cerebrovasculosa was found along the whole extent of the cranial spinal cord, while more caudally, all axial organs showed a normal histological structure. Our findings confirmed a different origin for the cranial and caudal parts of the human spinal cord. The appearance of dysraphic disorders corresponded to the time of primary neurulation; therefore, they resulted in the faulty formation of the cranial spinal cord. Normally formed caudal spinal cord appears during secondary neurulation at later developmental stages.

Electronic Resource