No abstract

Next-generation sequencing experiments have shown that microRNAs (miRNAs) are expressed in many different isoforms (isomiRs), whose biological relevance is often unclear. We found that mature miR-21, the most widely researched miRNA because of its importance in human disease, is produced in two prevalent isomiR forms that differ by 1 nt at their 3′ end, and moreover that the 3′ end of miR-21 is posttranscriptionally adenylated by the noncanonical poly(A) polymerase PAPD5. PAPD5 knockdown caused an increase in the miR-21 expression level, suggesting that PAPD5-mediated adenylation of miR-21 leads to its degradation. Exoribonuclease knockdown experiments followed by small-RNA sequencing suggested that PARN degrades miR-21 in the 3′-to-5′ direction. In accordance with this model, microarray expression profiling demonstrated that PAPD5 knockdown results in a down-regulation of miR-21 target mRNAs. We found that disruption of the miR-21 adenylation and degradation pathway is a general feature in tumors across a wide range of tissues, as evidenced by data from The Cancer Genome Atlas, as well as in the noncancerous proliferative disease psoriasis. We conclude that PAPD5 and PARN mediate degradation of oncogenic miRNA miR-21 through a tailing and trimming process, and that this pathway is disrupted in cancer and other proliferative diseases.nucleotidyl transferase | microRNA processing

The lizard genus Gekko consists of over 30 species distributed in Asia and Oceania. From the insular region of East Asia including Japan and Taiwan, 9 species (G. hokouensis, G. japonicus, G. shibatai, G. tawaensis, G. vertebralis,G. yakuensis, and 3 undescribed species) are currently recognized. We made karyological analyses for all these species. Their karyotypes invariably consisted of 2N = 38 chromosomes, but exhibited considerable variation in fundamental number (ranging from 56–62). Substantial chromosomal variation was detected even among populations of a morphologically relatively uniform species, G. hokouensis. Populations of G. hokouensis from the central and northern Ryukyus exhibited prominent female heteromorphic (i.e., ZW type) sex chromosomes. Populations of the southern Ryukyus exclusive of Yonagunijima also had ZW sex chromosomes, whose heteromorphisms were, however, much less prominent. The other G. hokouensis populations including the topotypic continental representatives and the population from Yonagunijima of the southern Ryukyus exhibited no sex chromosome heteromorphism at all. These results strongly suggest that G. hokouensis in the current taxonomic definition actually includes more than 2 species. The process of chromosomal evolution in the East Asian Gekko is hypothesized.

ABSTRACT:In order to develop a highly efficient method for mass production of triploid Pacific abalone Haliotis discus hannai, caffeine treatment that is safe and inexpensive was optimized. To . suppress the first meiotic division, fertilized eggs were exposed to either a 10-or 15-mM caffeine solution for 24 min beginning at 12 min after fertilization. In most treated batches, the rates of cleaved eggs showed no significant difference from the control batches. However, in most treated batches, the rates of occurrence of normal larvae and the survival rates of the early juveniles were significantly lower than those of the controls. The triploid rates at 6 days to 11 months after settlement in all the treated batches were extremely high (91-100%). There was no significant difference in the mean triploid rates between 10-and 15-mM caffeine treatments. These results suggest that both treatment conditions were conducive to triploid abalone production. One live 2n/3n mosaic specimen was found in the treated batches. However, since the frequency of mosaic was extremely low, the mosaicism would probably not have an adverse effect on the stable production of triploid abalones.

No abstract

The telomere sequence type (TTAGGG)n is known to be distributed in various phyla in the Animalia and in Mastigophora (Protista). However, the telomere type of Porifera (sponges), a phylum comprising the lowest multicellular animals, has not been reported. In this study, we examined the three sponge species Leucetta chagosensis, Halichondria japonica, and Halichondria panicea for the presence of the telomere type (TTAGGG)n by fluorescence in situ hybridization (FISH). The oligonucleotide probe (TTAGGG)7 clearly displayed signals on the interphase nuclei of all three sponges. In contrast, the (TTAGG)7 probe, which has one base fewer than (TTAGGG)7, did not display the signals. These results suggest that the telomeres of the three sponges consist of (TTAGGG)n, which is identical to the sequence type found in many higher multicellular animals and in Mastigophora. Additionally, this is the first study to reveal a telomere sequence type for Porifera. Moreover, these results suggest that Porifera are phylogenetically related to Mastigophora, and supports the general theory that Porifera evolved from Mastigophora. Further, this study strongly suggests that the origin of the (TTAGGG)n telomere sequence is to be found in a common ancestor of either the Bilateria and Porifera, or the Protista.

No abstract

The authors regret that Luba M. Pardo was omitted in error from the author list of the original version of this Data Descriptor. This omission has now been corrected in the HTML and PDF versions. The authors also regret that Anemieke Rozemuller was omitted in error from the Acknowledgements of the original version of this Data Descriptor. This omission has now been corrected in the HTML and PDF versions.