Senescence-associated β-galactosidase (SAβ-gal). Acidic β-galactosidase activity that occurs in senescent cells; used as a senescence biomarker.

The chromosome number in the caddis-fly, Glyphotaelius pellucidus (Retz.) is: 211 d' = 60, ~ = 69; n 6 = 30, ~ : 29, 30. The sex determining mechanism is XX-XO, the female being the heterogametic sex. The sex element is heteropycnotic at oogonial prometaphase and at oocyte pachytene. There are no chiasmata at oocyte diakinesis, whereas one or two of these occur per bivalent in the male. The smallest bivalent has a delayed pairing at spermatocyte diakinesis.