Analysis of cumene (isopropylbenzene) degradation genes from Pseudomonas fluorescens IP01.

We obtained the DNA fragments encoding 2-hydroxy-6-oxo-7-methylocta-2,4-dienoic acid (HOMODA) hydrolase in the cumene (isopropylbenzene) degrader Pseudomonas fluorescens strain IP01 via PCR using two synthesized oligonucleotides corresponding to the conserved regions within known meta-cleavage compound hydrolases. Following colony hybridization using the amplified DNA as a probe, a 4.5-kb HindIII fragment was isolated from P. fluorescens IP01. After determining the nucleotide sequence of this fragment, three open reading frames (ORF11 [cumH], ORF12 [cumD], and ORF13) were identified. The deduced amino acid sequence of ORF12 showed homology with meta-cleavage compound hydrolases encoded by the tod, dmp, xyl, and bph operons. Although the product of ORF12 was found to exhibit HOMODA and 2-hydroxy-6-oxohepta-2,4-dienoic acid (HOHDA) hydrolase activities, it did not exhibit 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid (HOPDA) hydrolase activity. The deduced amino acid sequence of ORF11 showed 40.4% homology with the sequence of todX in Pseudomonas putida F1 (Y. Wang, M. Ralings, D. T. Gibson, D. Labbé, H. Bergeron, R. Brousseau, and P. C. K. Lau, Mol. Gen. Genet. 246:570-579, 1995). The nucleotide sequence of ORF13 and its flanking region showed strong homology (91.0%) with IS52 from Pseudomonas savastanoi (Y. Yamada, P.-D. Lee, and T. Kosuge, Proc. Natl. Acad. Sci. USA 83:8263-8267, 1982). By characterization of cumH and cumD, the entire cum gene cluster from the cumene-degrader P. fluorescens IP01 (cumA1A2A3A4BCEGFHD) has been identified.     

The second phantom aquatic leaf beetle in Japan: Macroplea mutica rediscovery in the wetlands (Coleoptera: Chrysomelidae)

Wetland biodiversity is currently declining on a global scale. Wetland biodiversity understanding is critical for determining the wetlands' conservation value. In this study, Macroplea Samouelle, 1819 (Coleoptera: Chrysomelidae) was discovered in Aomori Prefecture, Honshu Island, Japan. Only two Macroplea species have been recorded in Japan, M. japana (Jacoby, 1885) and M. mutica (Fabricius, 1792). Macroplea japana had been unrecorded for 60 years before being rediscovered in Honshu Island in 2022, and a single adult M. mutica female was discovered in Hokkaido Prefecture in 2003. The discovered individuals were concluded to be M. mutica based on morphological and molecular analyses. Although morphological differences were observed with the Eurasian M. mutica individuals, the male genitalia was nearly identical to M. mutica. For the molecular phylogenetic analysis based on COI and 28S sequences, Macroplea individuals in Japan were clustered with M. mutica on the Eurasian Continent. This is the first record of this species on Honshu Island (and the second in Japan), as well as the first record of adult males. This species would require conservation policies and additional distributional surveys.     

Intraspecific brood-mixing of the cichlid fishPerissodus microlepis in Lake Tanganyika

Synopsis The frequency and origin of intraspecific brood-mixing in the biparental cichlid fishPerissodus microlepis were investigated by the cohort analysis of schooling young and the underwater observation of guarding parents. The cohort analysis showed that brood-mixing started from the early guarding state when the young were smaller than 10 mm standard length and nearly all schools of young larger than 16 mm contained alien young from up to 6 broods. Brood farming-out of this fish, which was originally proposed to be a way adopted only by a deserted parent, was performed also by paired parents. We suggest that brood-mixing inP. microlepis is attributed mainly to brood farming-out by paired and deserted parents.