kamili binadamu genome sequence of the two X chromosomes and autosomes from the female tissue derived cell line has been completed. This includes the 8% of the genome sequence that was missing in the original draft that was released in 2001.
kamili binadamu genome sequence of the entire 3.055 billion base pairs has been revealed by the Telomere-to-Telomere (T2T) Consortium. This represents the largest improvement to the binadamu kumbukumbu genome released in 2001 by Celera Genomics and the International Binadamu Genome Sequencing Consortium. That genome sequence covered most of the euchromatic regions while either leaving out the heterochromatin regions or erroneous representation. These regions comprise 8% of the binadamu genome that has finally been revealed. The new T2T-CHM13 reference1 inajumuisha mfuatano kamili wa otosomes zote 22 pamoja na Chromosome X. Mfuatano huu mpya wa marejeleo pia umerekebisha makosa mengi, na umeongeza takriban bp milioni 200 za mfuatano wa riwaya zenye nakala 2,226 za jeni, kati ya hizo 115 zinatabiriwa kuwa usimbaji wa protini.
The current GRCh38.p13 reference genome has been as a result of two major updates, one in 2013 and the other one on 2019 on the 2001 Celera genome sequence. However, it still had 151 million base pairs of unknown sequence distributed throughout the genome, including pericentromeric and sub telomeric regions, duplications, gene and ribosomal DNA (rDNA) arrays, all of which are necessary for fundamental cellular processes. The new reference has been named as T2T-CHM13 as it comes from sequencing the DNA from CHM13 (Complete Hydatiform Mole) cell line and is performed by T2T consortium. The cell line is derived from abnormal fertilized egg or an overgrowth of tissue from the placenta in which women appears to be pregnant (false pregnancy), hence the sequence represents only of the two X chromosomes and autosomes of the female. Multiple sequence technologies have been put to use such as PacBio, Oxford Nanopore, 100X and 70X Illumina sequencers to name a few. The technological advances in sequencing have led to the sequencing of the remaining 8% as mentioned above.
Kizuizi pekee cha mlolongo wa T2T-CHM13 ni ukosefu wa kromosomu Y. Mpangilio huu kwa sasa unaendelea, kwa kutumia DNA kutoka kwa mstari wa seli ya HG002, ambayo ina 46 (jozi 23) na karyotype ya XY. Kisha mfuatano huo utakusanywa kwa kutumia mbinu zilezile zilizotengenezwa kwa homozygous CHM13 genome.
Upatikanaji wa T2T-CHM13 kama marejeleo mapya genome inawakilisha mafanikio makubwa ambayo yatasaidia kuelewa jukumu la mikoa ya heterochromatin na kusaidia kuelewa athari zake kwenye michakato ya seli kwa undani zaidi. Hadi upangaji wa kromosomu Y ukamilike, hii itatumika kama jeni la marejeleo kwa tafiti za siku zijazo katika kuelewa michakato na utendakazi wa seli.
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Marejeo
- Nurk S, Koren S, Rhie A, Rautiainen M, Bzikadze A V, Mikheenko A et al. The complete sequence of a binadamu genome bioRxiv 2021.05.26.445798; DOI: https://doi.org/10.1101/2021.05.26.445798
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