Reina Castro-Longoria

Ovarian development and size at sexual maturity of the Mexican spiny lobster Panulirus inflatus

Abstract The ovarian development and the size at sexual maturity of Panulirus inflatus (Bouvier) of the Mexican Pacific and Gulf of California coastal waters were determined monthly between August 2001 and July 2002, using 191 females with carapace lengths (CLs) ranging from 44.94 to 94.18 mm. The seasonal cycle of ovarian development was divided into seven stages. The diameter of mature oocytes differed depending on ovarianmaturity stage (inactive = 44–115 μm, developing = 115–192 μm, ripe = 285–138 μm, re‐developing = 85–158 μm, re‐ripe = 133–183 μm, spawned = 29–87 μm, and recovering = 33–58 μm). Size of the smallest mature female was 53.02 mm CL, and the size at which 50% of females reached sexual maturity was estimated as 63.73 mm CL. Mature females were present every month, indicating a continuous reproductive pattern, although gonadosomatic index values were highest between February and July, with the maximum value in June. Results from this study indicate that the present minimum legal size, based on other spiny lobster species, is too large for P. inflatus.

The Pacific oyster (Crassostrea gigas) Hsp70 modulates the Ostreid herpes virus 1 infectivity

Abstract The Ostreid herpes virus type 1 (OsHV‐1) is one of the most devastating pathogen in oyster cultures. Among several factors, as food limitation, oxygen depletion, salinity and temperature variations, episodes of “summer mortality” of the Pacific oyster Crassostrea gigas have also been associated with OsHV‐1 infection. Mortalities of C. gigas spat and juveniles have increased significantly in Europe, and contemporary mortality records of this mollusk in México have been associated with the occurrence of OsHV‐1. In the present study, the expression of the heat shock protein 70 gene from the Pacific oyster correlates with the abundance of DNA polymerase transcripts from the OsHV‐1. This may suggest that the induction on the expression of the Pacific oyster hsp70 may potentially participate in the immune response against the virus. Furthermore, this study reports for the first time a TEM representative image of the OsHV‐1 in aqueous solution, which possesses an icosahedral shape with a diameter of 70 nm × 100 nm. Finally, the examined sequence encoding the ORF4 of the OsHV‐1 isolate from northwest Mexico showed specific sequence variations when compared with OsHV‐1 isolates from distant geographical areas. Graphical abstract Figure. No Caption available. HighlightsWe studied the effect of OsHV‐1 on the expression of C. gigas hsp70.Hsp70 never returned to it amount of mRNA control organism level.Hsp70 levels were related to the infection level.In situ detection of host and pathogen genes in same tissues.First negative aqueous TEM images of the OsHV‐1.

Fatty acid and proximate composition of wild male and female king angelfish (Holacanthus passer) gonads during the ripe and spent developmental stages

Overfishing of king angelfish Holacanthus passer reduced populations in the Gulf of California. This study aimed to determine the fatty acid and proximate composition of male and female gonads, and the E2 concentration in plasma of wild organisms with different stages of gonadal development captured during early and mid-summer at El Datil, near Kino Bay, Sonora, Mexico, to help establish basic reproductive aspects and possibly to help develop the aquaculture of this ornamental species. Out of the 45 adult specimens analyzed, 66.7% were females and 33.3% were males; 16.7% of the females had ripe gonads while 83.3% had spent gonads, and 20% of males had ripe gonads while 80% had spent gonads, indicating they were reproducing earlier, likely in the spring. Females had smaller size but numerically greater gonadosomatic index (GSI) and condition factor (K) than males. Ripe and spent females showed no statistical differences in weight, length or K; however, ripe females showed significantly higher GSI (P = 0.0005) than spent females, 3.43 vs. 0.87%. Lipid content was higher in ripe gonads, with higher content of fatty acids. In both sexes, DHA was quantitatively the major fatty acid, (10.83-16.28 mg of DHA g-1 of gonad wet weight). The n-3/n-6 ratios varied from 1.99 to 3.54, lower for ripe organisms due to a higher content of ARA and n-6 derivatives. Gonad DHA content changed in relation to its developmental stage and it might serve as an additional maturation index. Information on the chemical composition and fatty acid profile of the gonads can be used as indicators of dietary lipid and essential fatty acid requirements of broodfish, which may contribute to the formulation of a balanced diet for the culture of this ornamental species.

G-C heterozygosis in mutS homolog2 as a risk factor to hereditary nonpolyposis colon cancer in the absence of a family medical history.

To detect the presence of point mutations in a small section of the mutS homolog2 (MSH2) gene in both healthy and affected persons treated at the General Hospital of the State of Sonora, a 353 base pair section of the MSH2 gene was amplified and sequenced from six persons affected by hereditary nonpolyposis colorectal cancer and from 19 healthy persons. The affected persons did not show the mutations reported in the scientific literature; however, six healthy persons were heterozygote and mutant-allele carriers. The heterozygote condition implies that carriers are candidates for the development of colorectal cancer. However, it is important to know the family medical history when investigating hereditary mutations.