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  - Kneitz, Susanne
A1  - Mishra, Rasmi R.
A1  - Chalopin, Domitille
A1  - Postlethwait, John
A1  - Warren, Wesley C.
A1  - Walther, Ronald B.
A1  - Schartl, Manfred
T1  - Germ cell and tumor associated piRNAs in the medaka and \(Xiphophorus\) melanoma models
JF  - BMC Genomics
N2  - Background
A growing number of studies report an abnormal expression of Piwi-interacting RNAs (piRNAs) and the piRNA processing enzyme Piwi in many cancers. Whether this finding is an epiphenomenon of the chaotic molecular biology of the fast dividing, neoplastically transformed cells or is functionally relevant to tumorigenesisis is difficult to discern at present. To better understand the role of piRNAs in cancer development small laboratory fish models can make a valuable contribution. However, little is known about piRNAs in somatic and neoplastic tissues of fish.

Results
To identify piRNA clusters that might be involved in melanoma pathogenesis, we use several transgenic lines of medaka, and platyfish/swordtail hybrids, which develop various types of melanoma. In these tumors Piwi, is expressed at different levels, depending on tumor type. To quantify piRNA levels, whole piRNA populations of testes and melanomas of different histotypes were sequenced. Because no reference piRNA cluster set for medaka or Xiphophorus was yet available we developed a software pipeline to detect piRNA clusters in our samples and clusters were selected that were enriched in one or more samples. We found several loci to be overexpressed or down-regulated in different melanoma subtypes as compared to hyperpigmented skin. Furthermore, cluster analysis revealed a clear distinction between testes, low-grade and high-grade malignant melanoma in medaka.

Conclusions
Our data imply that dysregulation of piRNA expression may be associated with development of melanoma. Our results also reinforce the importance of fish as a suitable model system to study the role of piRNAs in tumorigenesis.
KW  - small RNA-sequencing
KW  - melanoma
KW  - piRNA
KW  - fish model
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-146028
VL  - 17
IS  - 357
ER  -