Fig. 1.

Oxpecker plays a role in female fertility. (A) Oxp is a chromodomain-only containing gene that is found immediately upstream of HP1D in the D. melanogaster genome. It derived from a HP1D/Rhino gene duplication ∼10–15 million years ago. (B) Isogenic females that possess an intact Oxp (Oxp⁺) or not (Oxp¹) were crossed to wildtype males in egg-exhaustion experiments (see “Methods” section) that measured total progeny produced in their lifetime that developed to adulthood. Oxp deletion leads to a 20–25% drop in total progeny produced (“**” P < 0.05). (C) The effect of Oxp deletion on female fertility can be restored by an Oxp transgene. Compared with Oxp¹/Oxp¹female flies that exhibit compromised fertility, isogenic flies that express an Oxp transgene produce wildtype-like number of progeny.