Ultrastructure of the siphonous green algae Avrainvillea and Cladocephalus

PHYLOGENETIC ANALYSIS OF THE LARGE SUBUNIT RUBISCO GENE SUPPORTS THE EXCLUSION OF AVRAINVILLEA AND CLADOCEPHALUS FROM THE UDOTEACEAE (BRYOPSIDALES, CHLOROPHYTA)1

“…However, spherical structures occurring near the basal end of the CLS in D. tuberosus amyloplasts are similar to structures observed elsewhere only in the CLS of amyloplasts in Avrainvillea and Cladocephalus, while all other genera in the Bryopsidales seem to lack these structures (Roth and Friedmann 1987). Additionally, electrondense bodies contained in vesicles in species of Avrainvillea and Cladocephalus are similar in size and shape to structures found in D. tuberosus (Møestrup andHoffman 1973, Roth andFriedmann 1987), and these characters may be considered synapomorphies of the ACD clade. Moving from a marine habitat to an exclusively freshwater one would produce a whole new set of environmental factors to direct the evolution of D. tuberosus, possibly leading to rapid phenotypic changes.…”

“…For example, the CLS is present in chloroplasts from species of Avrainvillea, Boodleopsis, Callipsygma, Caulerpa, Chlorodesmis, Cladocephalus, Dichotomosiphon, Halimeda, Penicillus, Rhipilia, Rhipocephalus, Pseudochlorodesmis, and Udotea (Roth and Friedman 1987), and this may be a synapomorphy of the Halimedineae. However, Roth and Friedmann (1987) noted that the CLS in chloroplasts of Avrainvillea and Cladocephalus is Fig. 1.…”

“…It is possible that D. tuberosus arose from a marine alga, similar to species of Avrainvillea and Cladocephalus . It is unclear if the CLS of chloroplasts in D. tuberosus is similar to the CLS of Avrainvillea and Cladocephalus chloroplasts, as chloroplasts with a CLS are rare in D. tuberosus (Roth and Friedmann 1987) . However, spherical structures occurring near the basal end of the CLS in D. tuberosus amyloplasts are similar to structures observed elsewhere only in the CLS of amyloplasts in Avrainvillea and Cladocephalus, while all other genera in the Bryopsidales seem to lack these structures (Roth and Friedmann 1987) .…”

“…It is unclear if the CLS of chloroplasts in D. tuberosus is similar to the CLS of Avrainvillea and Cladocephalus chloroplasts, as chloroplasts with a CLS are rare in D. tuberosus (Roth and Friedmann 1987) . However, spherical structures occurring near the basal end of the CLS in D. tuberosus amyloplasts are similar to structures observed elsewhere only in the CLS of amyloplasts in Avrainvillea and Cladocephalus, while all other genera in the Bryopsidales seem to lack these structures (Roth and Friedmann 1987) . Additionally, electron‐dense bodies contained in vesicles in species of Avrainvillea and Cladocephalus are similar in size and shape to structures found in D. tuberosus (Møestrup and Hoffman 1973, Roth and Friedmann 1987), and these characters may be considered synapomorphies of the ACD clade.…”

“…In addition, cells of Avrainvillea and Cladocephalus contain unique, round, electron‐dense bodies in the cytoplasm; pyrenoids with tightly fitting starch sheaths that are discontinuous from the chloroplast stroma (unique among the Bryopsidales); and CLS of chloroplasts and amyloplasts different from other Udoteacean algae (Roth and Friedmann 1987). Roth and Friedmann (1987) suggested that these characters distinguish the genera Avrainvillea and Cladocephalus taxonomically from the rest of the Bryopsidales. On the basis of Roth and Friedman’s data, Bold and Wynne (1985) suggested that Avrainvillea and Cladocephalus may warrant exclusion from the Udoteaceae; however, they did not formally place Avrainvillea and Cladocephalus elsewhere.…”