Identification of phase relative genes in tetrasporophytes and female
gametophytes of Gracilaria/Gracilariopsis lemaneiformis (Gracilariales,
Rhodophyta)
Genes differentially expressed between tetrasporophytes and female
gametophytes of Gracilaria/Gracilariopsis lemaneiformis were isolated
by suppression subtractive hybridization (SSH) and screened by dot-blot
macro-arrays. Different expression profiles of selected clones based on
the results of dot-blot macro-arrays were verified using virtual
Northern blots. Totally, 14 phase relative cDNAs had been isolated and
sequence identified. Among them, seven cDNAs were respectively
homologous to crucial metabolic enzymes, Rab GTPase, RP42 homolog, and
two hypothetical proteins, while the rest did not have significant hits
in the databases examined. The results of virtual Northern blots
revealed that 11 cDNAs were differentially expressed between the two
samples, including 7 genes up-regulated in tetrasporophytes, 1
expressed exclusively in tetrasporophytes and 3 up-regulated in female
gametophytes. By densitometric analysis relative to GAPDH, 8 cDNAs
increased 1.3-4.2 fold and 3 decreased about 0.4-0.7 fold in
tetrasporophytes compared to female gametophytes. The present study
provides the first insight into genes that may involve in phase
differentiation in G. lemaneiformis