21. The first 22 pairs of chromosomes ( called autosomes ) are numbered from 1 to 22, from largest to smallest. 22. Humans have 23 pairs of chromosomes, often split into the 22 pairs of autosomes and one pair of sex chromosomes. 23. Their experiments have shown how the ratio of sex chromosomes to autosomes can initiate a novel regulatory pathway involving RNA processing. 24. Fridolfsson's team has found evidence that the sex chromosomes of birds are indeed descended from an ancestral pair of autosomes . 25. Spinal muscular atrophy is inherited in an autosomal recessive pattern, which means that the defective gene is located on an autosome . 26. The possible interactions of Y chromosome are X-Y, Y-autosome and Y-cytoplasm ( Paras 2006 ). 27. The short and long arms of the pair of submetacentric autosomes correspond respectively to the 27th and 1st chromosomes in cattle and goats. 28. As well as autosomes , human neocentromeres have also been observed in sex chromosomes, and correlate with some sex-linked diseases. 29. The results were that balanced gene expression between X and autosomes gene expression was decreased by 10 15 % no matter the method of inhibition. 30. The animal has a karyotype of 46 chromosomes, with a total of 50 major arms on the autosomes ( non-sex chromosomes ).
