Adineta is a genus of rotifers belonging to the family Adinetidae. Species of this genus are found in Europe, Northern America, Australia and the southernmost parts of the Southern Hemisphere.
Species
There are currently 19 species discovered with A. vaga having five subspecies:
Adineta acuticornis Adineta barbata Adineta bartosi Adineta beysunae Adineta coatsi Adineta cuneata Adineta editae Adineta elongata Adineta emsliei Adineta fontanetoi Adineta glauca Adineta gracilis Adineta grandis Adineta longicornis Adineta oculata Adineta ricciae Adineta steineri Adineta tuberculosa Adineta vaga Adineta vaga major Adineta vaga minor Adineta vaga rhomboidea Adineta vaga tenuicornis Adineta vaga vaga
Adineta vaga Adineta vaga is a species belonging to this genus with four subspecies: A. v. major, A. v. minor, A. v. rhomboidea, and A. v. vaga. A member of this species was uncovered from permafrost in northeastern Siberia dating to around 24,000 years before present. However it was still alive in a frozen state making it the longest reported case of rotifer survival in a frozen state.
Genome The genome of Adineta vaga is tetraploid. It is composed mainly of anciently duplicated segments and less divergent allelic regions. Its allelic regions are rearranged and sometimes even found on the same chromosome which is in contrast to sexual species of this genus.
Meiosis Until recently, it was considered that the reproductive mode of bdelloid rotifers is mitotic parthenogenesis. However, recent research with Adineta vaga now supports a meiotic derived oogenesis with an altered meiosis I stage. During this stage homologous chromosomes associate, likely undergo recombinational repair of DNA damage and then separate, but do not segregate into haploid nuclei.
References