# genes in human genome?

18,308 genes according to Carl Zimmer via PANTHER

As Carl Zimmer notes, the presumed number of genes in the human genome has been steadily declining over the years.  Early estimates were in the 100K range.  For historical perspective, Lee Rowen won the GeneSweep competition back in 2003 for betting that the human genome contained 25,947 genes — the lowest estimate in the entire competition.

(hat tip, Hsien)

ORNL, How Many Genes in the Human Genome?

Comments

One Response to “# genes in human genome?”

  1. Misha Angrist on March 19th, 2007 12:21 pm

    Hi Jason:

    I can’t say anything about PANTHER as I’m not familiar with it. However, last year I had lengthy email exchange with a curator at NCBI trying to get at the same question: how many genes in the human genome? At that time (April 2006), NCBI’s totals were as follows:

    Protein coding genes:
    16787 gene with protein product, function known or
    inferred
    5137 gene with protein product, function unknown
    26 gene with protein product, inferred

    Genes that do not encode a protein:
    125

    Named structural RNAs:

    19 RNA, Cajal body-specific
    331 RNA, micro
    7 RNA, ribosomal
    54 RNA, small nuclear
    111 RNA, small nucleolar
    62 RNA, transfer

    Immunoglobulin and T-cell receptor segments:
    440

    Pseudogenes:
    3113 pseudogene, not transcribed
    249 pseudogene, transcribed

    type unknown (some expression, the product is under review)
    313

    Models on the Reference assembly (and thus very tentative)
    4160 protein-coding
    2476 pseudogenes

    The grand total was 33,410 for gene records with annotated reference sequences. Throw in the rest and you get about 39,000. From April 1 2006 (38277) to last Friday, March 16 (38672), the Entrez gene record count had shrunk by 605. Not an insignificant number, but a far cry from 25k to 18k. And if you look at the monthly record:

    http://www.ncbi.nlm.nih.gov/projects/Gene/gentrez_stats.cgi?TAXORG=&KING=All&GO=GO&QUICK=9606

    you see that from Feb 2004 to Mar 2006, or more than two years, the number was always within hailing distance of 33,000, +/- a few hundred. Then suddenly a big jump to 39,000 last April–a genetic bumper crop apparently.

    My point is that gene counts are dynamic. Yes there may be some shrinkage, but how many transcribed small RNAs remain to be discovered? (Are we really still wedded to the idea that you have to code for protein in order to be called a real gene?) Also, as I’m sure you know, 3x sequencing of Jim Watson’s genome has turned up some stuff that’s not in GenBank. Maybe it’s all heterochromatic “junk,” but right now we don’t know.

    IMO, counting genes is a tricky business, like conducting a census where one’s counting methods are constantly improving and the definition of who/what counts is a moving target.

Leave a Reply




You may use HTML tags in your comment. Please be patient, comments may take a while to post.

Subscribe without commenting