Chromosome Research

, Volume 18, Issue 5, pp 575–586

Characterisation of the chromosome fusions in Oreochromis karongae

  • Jose C. Mota-Velasco
  • Irani Alves Ferreira
  • Marcelo B. Cioffi
  • Konrad Ocalewicz
  • Rafael Campos-Ramos
  • Andrey Shirak
  • Bo-Young Lee
  • Cesar Martins
  • David J. Penman
Article

DOI: 10.1007/s10577-010-9141-z

Cite this article as:
Mota-Velasco, J.C., Ferreira, I.A., Cioffi, M.B. et al. Chromosome Res (2010) 18: 575. doi:10.1007/s10577-010-9141-z

Abstract

Oreochromis karongae, one of the “chambo” tilapia species from Lake Malawi, has a karyotype of 2n = 38, making it one of the few species investigated to differ from the typical tilapia karyotype (2n = 44). The O. karongae karyotype consists of one large subtelocentric pair of chromosomes, four medium-sized pairs (three subtelocentric and one submetacentric) and 14 small pairs. The five largest pairs could be distinguished from each other on the basis of size, morphology and a series of fluorescence in situ hybridisation (FISH) probes. The largest pair is easily distinguished on the basis of size and a chromosome 1 (linkage group 3) bacterial artificial chromosome (BAC) FISH probe from Oreochromis niloticus. BAC clones from O. niloticus chromosome 2 (linkage group 7) hybridised to one of the medium-sized subtelocentric chromosome pairs (no. 5) of O. karongae, distinguishing the ancestral medium-sized pair from the three other medium-sized chromosome pairs (nos. 2, 3 and 4) that appear to have resulted from fusions. SATA repetitive DNA hybridised to the centromeres of all 19 chromosome pairs and also revealed the locations of the relic centromeres in the three fused pairs. Telomeric (TTAGGG)n repeats were identified in the telomeres of all chromosomes, and an interstitial telomeric site (ITS) was identified in three chromosomal pairs (no. 2, 3 and 4). Additionally, two ITS sites were identified in the largest chromosome pair (pair 1), confirming the origin of this chromosome from three ancestral chromosomes. SATA and ITS sites allowed the orientation of the fusions in pairs 2, 3 and 4, which all appear to have been in different orientations (q–q, p–q and p–p, respectively). One of these fusions (O. karongae chromosome pair no. 2) involves a small chromosome (equivalent to linkage group 1), which in O. niloticus carries the main sex-determining gene. 4′,6-Diamidino-2-phenyloindole staining of the synaptonemal complex in male O. karongae revealed the presumptive positions of the kinetochores, which correspond well to the centromeric positions observed in the mitotic karyotype.

Keywords

tilapia chambo Malawi cichlid FISH synaptonemal complex Cyp19b 

Abbreviations

BAC

Bacterial artificial chromosome

BSA

Bovine serum albumin

DAPI

4′,6-Diamidino-2-phenyloindole

DIG

Digoxygenin

DOP-PCR

Degenerate oligonucleotide primed PCR

FISH

Fluorescence in situ hybridisation

FITC

Fluorescin isothiocyanate

ITS

Interstitial telomeric site

LE

Lateral element (of an SC bivalent)

LG

Linkage group

MALDI-TOF

Matrix-assisted laser desorption/ionisation–time of flight

PI

Propidium iodide

SATA

Satellite DNA isolated from the tilapia genome by EcoRI digestion and electrophoresis

SC

Synaptonemal complex

SNP

Single nucleotide polymorphism

SSC

Saline-sodium citrate

Supplementary material

10577_2010_9141_MOESM1_ESM.tif (432 kb)
High resolution image(TIFF 431 kb)
10577_2010_9141_MOESM2_ESM.tif (572 kb)
High resolution image(TIFF 571 kb)
10577_2010_9141_MOESM3_ESM.tif (998 kb)
High resolution image(TIFF 998 kb)

Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  • Jose C. Mota-Velasco
    • 1
    • 2
  • Irani Alves Ferreira
    • 3
  • Marcelo B. Cioffi
    • 4
  • Konrad Ocalewicz
    • 1
    • 5
  • Rafael Campos-Ramos
    • 1
    • 6
  • Andrey Shirak
    • 7
  • Bo-Young Lee
    • 8
    • 9
  • Cesar Martins
    • 3
  • David J. Penman
    • 1
  1. 1.Institute of AquacultureUniversity of StirlingStirlingUK
  2. 2.Landcatch Natural SelectionThe e.Centre, Cooperage Way Business VillageClackmannanshireUK
  3. 3.Departamento de Morfologia, Instituto de BiociênciasUNESP–Universidade Estadual PaulistaBotucatuBrazil
  4. 4.Departamento de Genética e Evolução, Centro de Ciências Biológicas e da SaúdeUniversidade Federal de São CarlosSão CarlosBrazil
  5. 5.Department of IchthyologyUniversity of Warmia and Mazury in OlsztynOlsztynPoland
  6. 6.Centro de Investigaciones Biológicas del Noroeste S.C. (CIBNOR)La PazMexico
  7. 7.Institute of Animal Science, Agricultural Research OrganizationVolcani CenterBet DaganIsrael
  8. 8.Department of BiologyUniversity of MarylandCollege ParkUSA
  9. 9.Laboratory of Bioinformatics and Population Genetics, Department of Agricultural BiotechnologySeoul National UniversitySeoulRepublic of Korea

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