Fig. 1

PtVg4 gene is expressed in the ovaries and midgut glands only of female spiders. PCR and qPCR analyses of the sex- and tissue-specific expression of P. tepidariorum Vg (PtVg4). a Sex-specific expression of Vg in the whole body extract on the first day after mating. b Tissue-specific expression of the PtVg4 in female spiders on day 47 after leaving a cocoon. Total RNA samples were extracted from various female tissues: the nervous system and neuroendocrine system (NS + NS), ovaries (OV), the midgut glands (MG), hindgut (HG), integument (INT). c PtVg4 mRNA level [average ± SD] in female spiders in various ages – in the penultimate nymph stage (day 35 after leaving a cocoon), last nymphal stage (day 38), day that sexual maturation was reached (day 40), three days after mating (day 43) and the day of the first oviposition (day 47) in the midgut glands and in the ovaries. Lowercase letters indicate significant differences within the same tissue (Tukey’s multiple comparisons test, p ≤ 0.05)