Evolutionary dynamics of repetitive elements and their relationship with genome size in Acrididae.

It is widely accepted that repetitive elements (REs) represent the primary mechanism driving genome size variation across eukaryotes. The observed genome sizes and REs of 59 species within the Acrididae were obtained and characterized. The genome sizes observed ranged from 6.60 pg to 19.35 pg, while the proportion of REs varied from 57.92 % to 83.58 %. The primary contributors were identified as LTR (2.34 % ∼ 20.98 %) and LINEs (6.70 % ∼ 16.33 %). The results of ancestral reconstruction indicated that the proportion of REs in ancestral nodes was 69.53 %, which suggests that they have undergone extensive genome expansion or contraction. A significant positive correlation was identified between the proportion of REs and genome size. Transposable elements were found to account for approximately 41 % of the observed variation in genome size. Moreover, the LTR was identified as the most significant RE type in relation to genome size expansion within the Acrididae.