Identification and Characterization of the Gene Responsible for the O Mating Type Substance in .

The process of sexual reproduction in eukaryotes starts when gametes from two different sexes encounter each other. , a unicellular eukaryote, undergoes conjugation and uses a gametic nucleus to enter the sexual reproductive process. The molecules responsible for recognizing mating partners, hypothetically called mating-type substances, are still unclear.

Immaturin-Nuclease as a Model System for a Gene-Programmed Sexual Development and Rejuvenescence in Life History.

Fertilization-initiated development and adult-onset aging are standard features in the life history of eukaryotes. In , the number of cell divisions after the birth of a new generation is an essential parameter of sexual phase transition and aging. However, the gene driving this process and its evolutionary origin have not yet been elucidated.

Micromanipulation in Paramecium: From non-mendelian inheritance to the outlook for versatile micromachines.

This review addresses nine areas of knowledge revealed by micromanipulations performed with Paramecium. Microinjection has shown that sexual maturation and senescence of Paramecium caudatum is a programmed process conducted by a specific gene and its product protein. In Paramecium tetraurelia, autogamy was revealed to depend on the number of DNA syntheses rather than the number of cell divisions in clonal aging.

Identification of two nickel ion-induced genes, NCI16 and PcGST1, in Paramecium caudatum.

Here, we describe the isolation of two nickel-induced genes in Paramecium caudatum, NCI16 and PcGST1, by subtractive hybridization. NCI16 encoded a predicted four-transmembrane domain protein (∼16 kDa) of unknown function, and PcGST1 encoded glutathione S-transferase (GST; ∼25 kDa) with GST and glutathione peroxidase (GPx) activities. Exposing cells to cobalt chloride also caused the moderate upregulation of NCI16 and PcGST1 mRNAs.

Studies of Paramecium caudatum by means of scanning electron microscope and projection X-ray microscope.

Samples of Paramecium caudatum are observed by means of a scanning electron microscope (SEM) and a projection X-ray microscope (XRM) with computer tomography (CT) function. The samples are fixed with two kinds of fixatives, glutaraldehyde and osmium-tetra oxide acid. After the fixation and replacement procedure with t-buthyl alcohol, the samples followed by a freeze drying, well retain their structures.

Direct observation of histone H2B-YFP fusion proteins and transport of their mRNA between conjugating Paramecia.

Cytoplasmic exchange between conjugating cells of Paramecium caudatum has been implicated by mating experiments using wild-type and behavioral mutant cells. To observe macromolecular transport between mating cells, we cloned and expressed the P. caudatum histone H2B gene as a fusion protein attached to an enhanced yellow fluorescent protein (YFP) named PcVenus.

FBN2, FBN1, TGFBR1, and TGFBR2 analyses in congenital contractural arachnodactyly.

FBN2, FBN1, TGFBR1, and TGFBR2 were analyzed by direct sequencing in 15 probands with suspected congenital contractural arachnodactyly (CCA). A total of four novel FBN2 mutations were found in four probands (27%, 4/15), but remaining the 11 did not show any abnormality in either of the genes. This study indicated that FBN2 mutations were major abnormality in CCA, and TGFBR and FBN1 defects may not be responsible for the disorder.

Transformation of Paramecium caudatum with a novel expression vector harboring codon-optimized GFP gene.

We have developed a novel expression vector, pTub-tel3, for transformation in Paramecium caudatum. The vector was constructed by cloning P. caudatum alpha-tubulin 5' and 3' non-coding regions.