TY  - JOUR
A1  - Du, Kang
A1  - Wuertz, Sven
A1  - Adolfi, Mateus
A1  - Kneitz, Susanne
A1  - Stöck, Matthias
A1  - Oliveira, Marcos
A1  - Nóbrega, Rafael
A1  - Ormanns, Jenny
A1  - Kloas, Werner
A1  - Feron, Romain
A1  - Klopp, Christophe
A1  - Parrinello, Hugues
A1  - Journot, Laurent
A1  - He, Shunping
A1  - Postlethwait, John
A1  - Meyer, Axel
A1  - Guiguen, Yann
A1  - Schartl, Manfred
T1  - The genome of the arapaima (Arapaima gigas) provides insights into gigantism, fast growth and chromosomal sex determination system
JF  - Scientific Reports
N2  - We have sequenced the genome of the largest freshwater fish species of the world, the arapaima. Analysis of gene family dynamics and signatures of positive selection identified genes involved in the specific adaptations and unique features of this iconic species, in particular it’s large size and fast growth. Genome sequences from both sexes combined with RAD-tag analyses from other males and females led to the isolation of male-specific scaffolds and supports an XY sex determination system in arapaima. Whole transcriptome sequencing showed that the product of the gland-like secretory organ on the head surface of males and females may not only provide nutritional fluid for sex-unbiased parental care, but that the organ itself has a more specific function in males, which engage more in parental care.
KW  - Genome
KW  - Genomics
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-201333
VL  - 9
ER  - 
TY  - JOUR
A1  - Dedukh, Dmitrij
A1  - Da Cruz, Irene
A1  - Kneitz, Susanne
A1  - Marta, Anatolie
A1  - Ormanns, Jenny
A1  - Tichopád, Tomáš
A1  - Lu, Yuan
A1  - Alsheimer, Manfred
A1  - Janko, Karel
A1  - Schartl, Manfred
T1  - Achiasmatic meiosis in the unisexual Amazon molly, Poecilia formosa
JF  - Chromosome Research
N2  - Unisexual reproduction, which generates clonal offspring, is an alternative strategy to sexual breeding and occurs even in vertebrates. A wide range of non-sexual reproductive modes have been described, and one of the least understood questions is how such pathways emerged and how they mechanistically proceed. The Amazon molly, Poecilia formosa, needs sperm from males of related species to trigger the parthenogenetic development of diploid eggs. However, the mechanism, of how the unreduced female gametes are produced, remains unclear. Cytological analyses revealed that the chromosomes of primary oocytes initiate pachytene but do not proceed to bivalent formation and meiotic crossovers. Comparing ovary transcriptomes of P. formosa and its sexual parental species revealed expression levels of meiosis-specific genes deviating from P. mexicana but not from P. latipinna. Furthermore, several meiosis genes show biased expression towards one of the two alleles from the parental genomes. We infer from our data that in the Amazon molly diploid oocytes are generated by apomixis due to a failure in the synapsis of homologous chromosomes. The fact that this failure is not reflected in the differential expression of known meiosis genes suggests the underlying molecular mechanism may be dysregulation on the protein level or misexpression of a so far unknown meiosis gene, and/or hybrid dysgenesis because of compromised interaction of proteins from diverged genomes.
KW  - meiosis
KW  - parthenogenesis
KW  - synaptonemal complex
KW  - recombination
KW  - crossing-over
KW  - achiasmatic
KW  - transcriptome
KW  - oogenesis
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-325128
VL  - 30
IS  - 4
ER  -