Effects of <Emphasis Type="Italic">Dracontomelon duperreanum</Emphasis> Leaf Litter on the Growth and Photosynthesis of <Emphasis Type="Italic">Microcystis aeruginosa</Emphasis>

This study investigated the use of Dracontomelon duperreanum leaf litter extract (DDLLE) in inhibiting the growth and photosynthesis of the algae Microcystis aeruginosa. The goal of the study was to evaluate a potential solution for cyanobacterial bloom prevention. M. aeruginosa was exposed to extract concentrations from 0.4 to 2.0 g L^?1. Chlorophyll-a (Chl-a) content and photosynthesis levels were assessed using pulse amplitude modulated fluorimetry phytoplankton analyzer. Results suggested that the extract could efficiently suppress M. aeruginosa growth. The content of Chl-a was only 19.0 µg L^?1 and achieved 96.0% inhibition rate when exposed to 2.0 g L^?1 on day 15. Growth rate in response to different extract concentrations were consistent with changes in the photosynthesis efficiency (alpha), maximal relative electron transport rate and maximal photochemical efficiency of photosystem II (F _v /F _m ). Furthermore, several kinds of volatile chemicals and their concentrations in DDLLE had been identified by GC–MS, which of them play major role to suppress the growth of M. aeruginosa should be further studied.     

Growth Recovery of <Emphasis Type="Italic">Lemna gibba</Emphasis> and <Emphasis Type="Italic">Lemna minor</Emphasis> Following a 7-Day Exposure to the Herbicide Diuron

In agricultural catchments, aquatic ecosystems can experience a pulse exposure to pesticides. Following such exposure, non-target organisms that are not extirpated may recover. This paper investigates the potential of two duckweed species (Lemna minor and Lemna gibba) to recover from a 7-day exposure to different concentrations (0.4–208 µg L^?1) of the herbicide diuron. There was significant inhibition in the growth and biomass after the initial 7-day exposure (e.g. frond number EC₅₀ = 59.2 and 52.2 µg L^?1 for L. minor and L. gibba, respectively). Following transfer to clean media, recovery (the highest concentration yielding no significant difference in the effect endpoint from the control) was observed for all effects endpoints at concentrations ranging 60–111 µg L^?1 for L. minor and 60–208 µg L^?1 for L. gibba. These results suggest that recovery is possible for primary producers at environmentally relevant concentrations considered significant in ecological risk assessment.     

Effects of Ammonia and Density on Filtering of Commensal and Pathogenic <Emphasis Type="Italic">Escherichia coli</Emphasis> by the Cladoceran <Emphasis Type="Italic">Daphnia magna</Emphasis>

Grazing by cladocerans can reduce the survival of enteric bacteria associated with fecal pollution. This study examined the potential of Daphnia magna to filter commensal and pathogenic Escherichia coli of human origin. Grazing on commensal and pathogenic bacteria was comparable, but slightly greater at 20 compared to 15 and 25°C. Filtering activity was strongly dependent on D. magna and E. coli densities at environmentally relevant bacterial concentrations. Maximum feeding rates were >10⁷ cells h^?1 daphnid^?1, clearance rates were 1–6 mL h^?1 daphnid^?1, and filtering was independent of bacterial cell sizes between 0.7 and 1.8 µm. Filtering and ingestion of E. coli by D. magna was susceptible to acute inhibition by unionized ammonia with a 24 h EC50 of 0.18 mg L^?1 NH₃–N, and a LOEC of 0.09 mg L^?1 NH₃–N. The study indicated that biological and chemical constraints should be considered when applying Daphnia for attenuation of fecal pollution.     

Assessment of Cadmium Scavenging Potential of <Emphasis Type="Italic">Canna indica</Emphasis> L.

The aquatic plant, Canna indica L. (Indian shoot) of Cannaceae family was investigated to assess cadmium scavenging potential at 5, 10, 25, 50, 100 and 150 mg Cd L^?1 exposers. The results showed that Canna has considerable potential of cadmium accumulation, which was up to 58.69 and 10.13 mg Cd kg^?1 dry weight in root and shoot of Canna, respectively. The effects of different cadmium levels on biomass production of plant tissues were significantly (p?=?0.05) showed negative relation due to cadmium toxicity. The root concentration factor was higher than the bioconcentration factor which indicated the lower translocation factor of Canna. Considering the high root concentration factor, average bioconcentration factor, rapid growth and optimum adaptive properties up to 100 mg Cd L^?1 level, the Canna could be employed as an eco-friendly and efficient aquatic plant for cadmium scavenging. This study plays a potential role in remediation of cadmium contaminated wastewater.     

Effects of Water pH on Life History Parameters of a New Bosminid Cladocera: <Emphasis Type="Italic">Bosmina (Bosmina) Tripurae</Emphasis> (Korinek,Saha and Bhattachaya, 1999) in Laboratory Condition

The effects of water pH on life history parameters of Bosmina tripurae have been studied to determine the most suitable water pH desired for the maximum growth and development of this newly discovered cladoceran species. The study was carried out under the laboratory condition at 20?±?2°C. Five pH ranges 5.0?±?0.2, 6.0?±?0.2, 7.0?±?0.2, 8.0?±?0.2 and 9.0?±?0.2 with six replicates for each pH consisting of one animal in each Petri dish (80?×?15 mm) were used for the study. 20 mL of respective test medium was maintained with Chlorella sp. (2?×?10⁴?±?0.03 cells mL^?1) in each Petri dish throughout the experiment. Thirty (30) animals were observed daily to investigate different life history parameters like total life span, age at maturity, number of eggs, neonates and egg batches etc. at different condition. From the study it was found that acidic water (pH 5?±?0.2) is more suitable for the culture of Bosmina tripurae in laboratory condition.     

Effects of Low-Frequency Ultrasound on <Emphasis Type="Italic">Microcystis aeruginosa</Emphasis> from Cell Inactivation to Disruption

Ultrasound can be used to induce cell resonance and cavitation to inhibit cyanobacterial growth, but it can also lead to increase in dissolved nutrients because of cell disruption. This study investigated the process from cell inactivation to disruption of Microcystis aeruginosa. Algal cells were sonicated (at 35 kHz) under various intensities and durations. Results showed that chlorophyll a content and F_v/F_m values decreased slightly within the first 5 min. Superoxide dismutase activity was stimulated and its peak value appeared at the fifth minute. After 20 min, considerable number of ruptured cells were observed and the concentrations of dissolved nitrogen and phosphorus increased rapidly. Finally, ammonia and nitrate merely composed a small portion of dissolved nitrogen. This study demonstrated that excessive ultrasound treatment can significantly rupture algal cells and lead to the release of cellular inclusions, which may cause ecological issues or public health problems. Based on our findings, ultrasonic intensity controlled at 0.035 W/mL and applied for a duration of 20 min delivers the optimal result in effectively inhibiting physiological activities of Microcystis aeruginosa without marked cell disruption. This will ultimately help to achieve algal control, while conserving energy and preserving the environment and human health.     

Bioaccumulation of Uranium and Thorium by <Emphasis Type="Italic">Lemna minor</Emphasis> and <Emphasis Type="Italic">Lemna gibba</Emphasis> in Pb-Zn-Ag Tailing Water

This study focused on the ability of Lemna minor and Lemna gibba to remove U and Th in the tailing water of Keban, Turkey. These plants were placed in tailing water and individually fed to the reactors designed for these plants. Water and plant samples were collected daily from the mining area. The plants were ashed at 300°C for 1 day and analyzed by ICP-MS for U and Th. U was accumulated as a function of time by these plants, and performances between 110?% and 483?% for L. gibba, and between 218?% and 1194?% for L. minor, were shown. The highest Th accumulations in L. minor and L. gibba were observed at 300?% and 600?% performances, respectively, on the second day of the experiment. This study indicated that both L. gibba and L. minor demonstrated a high ability to remove U and Th from tailing water polluted by trace elements.     

Allelopathic Effects of <Emphasis Type="Italic">Myriophyllum aquaticum</Emphasis> on Two Cyanobacteria of <Emphasis Type="Italic">Anabaena flos-aquae</Emphasis> and <Emphasis Type="Italic">Microcystis aeruginosa</Emphasis>

Allelopathy has been proposed as a sustainable means to control undesired algal growth and to reduce blooms threatening freshwater systems worldwide. In this study, the allelopathic effects of Myriophyllum aquaticum and its exudate on two typical bloom-forming cyanobacteria, Microcystis aeruginosa and Anabaena flos-aquae, were investigated under laboratory conditions. The growth of the cyanobacteria was strongly inhibited by live M. aquaticum while the primary addition of M. Aquaticum exudates had a significant inhibitory effect on the growth of M. aeruginosa but not A. flos-aquae. The results suggested that the persistent release of allelochemicals from live M. aquaticum was needed to effectively constrain the growth of A. flos-aquae. Analysis of cyanobacterial physiological indexes indicated that M. aquaticum produced an inhibitory effect on SOD enzyme activity of A. flos-aquae, while it affected membrane lipid peroxidation in M. aeruginosa. The results show the potential of M. aquaticum to mitigate cyanobacterial blooms in coexistence systems.     

Contamination Profile of DDTs in the Shark <Emphasis Type="Italic">Somniosus microcephalus</Emphasis> from Greenland Seawaters

DDT isomers were detected in all the liver and muscle samples of Greenland sharks Somniosus microcephalus (n?=?15) caught in Greenland seawaters. The mean concentrations of ΣDDTs (sum of o,p’ and p,p’ DDT, DDD, and DDE isomers) were 1094?±?818 ng/g lipid weight (lw) in the muscle and 761?±?416 ng/g lw in the liver. The p,p’-DDE accounted for 48%?±?41% and 53%?±?54% of the total DDT residue in the white muscle and liver, respectively. The lipid content was 48%?±?10% in the muscle and 43%?±?17% in the liver. Female sharks showed the highest concentrations of ΣDDTs. The youngest shark showed higher concentrations of ΣDDTs in the liver than the older sharks. To our knowledge, this is one of the few investigations on DDT levels in S. microcephalus where concentrations were correlated to lipid content and sex/size.     

Arbuscular Mycorrhizal Fungi Favor the Initial Growth of <Emphasis Type="Italic">Acacia mangium,Sorghum bicolor</Emphasis>, and <Emphasis Type="Italic">Urochloa brizantha</Emphasis> in Soil Contaminated with Zn,Cu, Pb,and Cd

This study evaluated the effect of inoculation with a mixture of spores of arbuscular mycorrhizal fungi (AMF) (Glomus macrocarpum, Paraglomus occultum, and Glomus sp.) on the initial establishment of Acacia mangium, Sorghum bicolor, and Urochloa brizantha in soil contaminated with heavy metals. The experiment was conducted in a greenhouse, in plastic pots containing 1.8 kg of soil, which presented 7200, 1140, 480, and 72 mg of Zn, Cu, Pb, and Cd, respectively. The chlorophyll content (SPAD index) of inoculated plants of A. mangium and U. brizantha was higher than those of non-inoculated plants (p?<?0.05). No differences were detected for the concentration of heavy metals in plant shoots, whether the plant was inoculated or not. However, inoculated plants had greater root length (S. bicolor and U. brizantha) (p?<?0.05) and greater plant height (A. mangium) (p?<?0.05). The present results demonstrate that the beneficial effects of AMF on plant growth and the alleviation of contaminants are imperative factors for the rehabilitation of soils contaminated with heavy metals.     

Leaf Composition of American Bur-Reed (<Emphasis Type="Italic">Sparganium americanum</Emphasis> Nutt.) to Determine Pesticide Mitigation Capability

American bur-reed (Sparganium americanum Nutt.), a common aquatic plant in the middle and eastern United States and Canada, is often located in water-retaining drainage areas. The purpose of this study was to determine the leaf composition of S. americanum, paying attention to the cuticular waxes and the epidermis, and its ability to sorb pesticides. S. americanum leaves (n?=?100) were collected in both early (June) and late (August) summer. Transverse sections of S. americanum were stained and studied with brightfield and fluorescence microscopy to estimate the structural and chemical nature of the leaf tissues cross sections. Mean total lipid content in early summer leaf samples (1.47?±?0.83 mg mL^?1) was significantly greater (alpha 0.05) than late summer leaves (0.15?±?0.36 mg mL^?1). In vitro analysis of epidermal peel permeability exposed to atrazine and malathion determined little to no sorption by the plant. Therefore, the structure of S. americanum leaves suggest this species does not have the capacity of sorbing these pesticides from runoff water.     

Heavy Metal Concentration in Largehead Hairtail (<Emphasis Type="Italic">Trichiurus lepturus</Emphasis> Linneaus, 1758) and Savalai Hairtail (<Emphasis Type="Italic">Lepturacanthus savala</Emphasis> (Cuvier, 1829)) Obtained from Karachi Fish Harbour,Pakistan

In this study, muscle samples gathered from Largehead hairtail (Trichiurus lepturus Linneaus, 1758) and Savali hairtail [Lepturacanthus savala (Cuvier, 1829)] from the Karachi Fish Harbour, Pakistan were analyzed to determine heavy metal concentrations (iron [Fe], zinc [Zn], copper [Cu], manganese [Mn], lead [Pb] and cadmium [Cd]) between January and December 2016. All samples were analyzed using the AAnalyst 700 Flame Atomic Absorption Spectrophotometer. It was observed that the average measured level of Fe, Zn, Cu, Mn, Pb and Cd in muscle were 77.72?±?47.84 µg/g, 20.34?±?8.49 µg/g, 2.23?±?1.16 µg/g, 0.57?±?0.36 µg/g, 0.20?±?0.16 µg/g and 0.42?±?0.19 µg/g for T. lepturus, respectively. Besides, the average level of the same metal concentrations in muscle for L. savala were 85.11?±?57.64 µg/g, 16.63?±?9.25 µg/g, 2.53?±?1.90 µg/g, 0.47?±?0.27 µg/g, 0.23?±?0.18 µg/g and 0.47?±?0.20 µg/g, respectively. The correlation between size groups and metal accumulation in muscle tissues were investigated for both fish. In terms of public risk assessment, the provisional tolerable weekly intake’s of various heavy metals were compared with the consumption of both fish. As a result of the analysis, Fe, Zn, Cu, Mn, Pb and Cd accumulations in muscle tissues of T. lepturus and L. savala collected from Karachi Fish Harbour Pakistan did not exceed limit values.     

The synergistic effect between the Mediterranean diet and <Emphasis Type="Italic">GSTP1</Emphasis> or <Emphasis Type="Italic">NAT2</Emphasis> SNPs decreases breast cancer risk in Greek-Cypriot women

Purpose

Xenobiotic metabolism is related to the interplay between diet and breast cancer (BC) risk. This involves detoxification enzymes, which are polymorphic and metabolise various dietary metabolites. An important characteristic of this pathway is that chemoprotective micronutrients can act not only as substrates but also as inducers for these enzymes. We investigated whether functional GSTP1 (p.Ile105Val-rs1695), NAT2 (590G>A-rs1799930) SNPs and GSTM1 and GSTT1 deletion polymorphisms could modulate the effect of the Mediterranean diet (MD) on BC risk, in Greek-Cypriot women.

Methods

Genotyping was performed on women from the MASTOS case–control study of BC in Cyprus. A 32-item food-frequency questionnaire was used to obtain dietary intake information. A dietary pattern, which closely resembles the MD (high loadings of vegetables, fruit, legumes and fish), was previously derived with principal component analysis and was used as our dietary variable.

Results

GSTT1 null genotype increased BC risk compared with the homozygous non-null GSTT1 genotype (OR 1.21, 95 % CI 1.01–1.45). Increasing adherence to the MD reduced BC risk in women with at least one GSTP1 Ile allele (OR for Ile/Ile = 0.84, 95 % CI 0.74–0.95, for Ile/Val = 0.73, 95 % CI 0.62–0.85) or one NAT2 590G allele (OR for 590 GG = 0.73, 95 % CI 0.63–0.83, for 590 GA = 0.81, 95 % CI 0.70–0.94). p interaction values were not, however, statistically significant.

Conclusion

The homozygous null GSTT1 genotype could be a risk allele for BC among Greek-Cypriot women. The anticarcinogenic effects of the high adherence to MD against BC risk could also be further enhanced when combined with the wild-type alleles of the detoxification GSTP1 or NAT2 SNPs.

     

Phytoremediation Potential of <Emphasis Type="Italic">Saccharina japonica</Emphasis> and <Emphasis Type="Italic">Sargassum horneri</Emphasis> (Phaeophyceae): Biosorption Study of Strontium

Strontium (Sr) is an important nuclide in nuclear polluted seawater. Algal biosorption is regarded as an efficient and cost-effective way to scavenge detrimental metal ions of low concentration from polluted waters. In this study, we selected two algal species (Saccharina japonica and Sargassum horneri) through comparing background Sr contents in six algal species and explored their potential to scavenge Sr of low concentration from seawater in culture conditions. It was found that biosorption of Sr in S. japonica and S. horneri increased in response to increased Sr concentrations in the seawater and S. horneri adsorbed more Sr than S. japonica. The equilibrium established in their biosorption process follows both Langmiur and Freundlich equations well. The Sr biosorption process of S. horneri fits the pseudo-second-order kinetic model well, implying that adsorption was the rate-limiting step of the biosorption process. Results suggest S. japonica and S. horneri could become efficient biosorbents for in situ scavenging Sr from nuclear polluted seawater.     

Relationships of alcohol dehydrogenase 1B (<Emphasis Type="Italic">ADH1B</Emphasis>) and aldehyde dehydrogenase 2 (<Emphasis Type="Italic">ALDH2</Emphasis>) genotypes with alcohol sensitivity,drinking behavior and problem drinking in Japanese older men

Objectives

Many East Asians have the genetic polymorphisms rs1229984 in alcohol dehydrogenase 1B (ADH1B) and rs671 in aldehyde dehydrogenase 2 (ALDH2). Here we analyzed the relationships of the two genotypes with alcohol sensitivity, drinking behavior and problem drinking among older and younger men living in rural areas of Japan.

Methods

The subjects were 718 Japanese men aged 63.3 ± 10.8 (mean ± SD), categorized into the older (≥65 years, n = 357) and younger (<65 years, n = 361) groups. Facial flushing frequency, drinking behavior and positive CAGE results were compared among the genotypes using Bonferroni-corrected χ² test and a multivariate logistic regression analysis adjusting for age, BMI and lifestyle factors.

Results

The frequency of ‘always’ facial flushing among the ADH1B*1/*2 carriers was significantly lower than that among the ADH1B*2/*2 carriers in the older group (P < 0.01). The alcohol consumption (unit/day) in the ADH1B*1/*2 carriers tended to be higher compared with that in the ADH1B*2/*2 carriers among the older group (P = 0.050). In the younger group, no significant differences in alcohol sensitivity and drinking habits were generally found among the ADH1B genotypes. The ADH1B*1/*1 genotype tended to be positively associated with problem drinking in the older group (P = 0.080) but not in the younger group. The ALDH2 genotypes consistently and strongly affected the alcohol sensitivity, drinking behavior and problem drinking in both the younger and older group.

Conclusions

We for the first time observed a significant difference in alcohol sensitivity between ADH1B*1/*2 and ADH1B*2/*2 in older men aged 65 and above.

     

Consumption of <Emphasis Type="Italic">Bifidobacterium animalis</Emphasis> subsp. <Emphasis Type="Italic">lactis</Emphasis> BB-12 in yogurt reduced expression of TLR-2 on peripheral blood-derived monocytes and pro-inflammatory cytokine secretion in young adults

Purpose

Probiotic bacteria modulate immune parameters and inflammatory outcomes. Emerging evidence demonstrates that the matrix used to deliver probiotics may influence the efficacy of probiotic interventions in vivo. The aims of the current study were to evaluate (1) the effect of one species, Bifidobacterium animalis subsp. lactis BB-12 at a dose of log10 ± 0.5 CFUs/day on immune responses in a randomized, partially blinded, 4-period crossover, free-living study, and (2) whether the immune response to BB-12 differed depending on the delivery matrix.

Methods

Healthy adults (n = 30) aged 18–40 years were recruited and received four treatments in a random order: (A) yogurt smoothie alone; smoothie with BB-12 added (B) before or (C) after yogurt fermentation, or (D) BB-12 given in capsule form. At baseline and after each 4-week treatment, peripheral blood mononuclear cells (PBMCs) were isolated, and functional and phenotypic marker expression was assessed.

Results

BB-12 interacted with peripheral myeloid cells via Toll-like receptor 2 (TLR-2). The percentage of CD14⁺HLA-DR⁺ cells in peripheral blood was increased in male participants by all yogurt-containing treatments compared to baseline (p = 0.0356). Participants who consumed yogurt smoothie with BB-12 added post-fermentation had significantly lower expression of TLR-2 on CD14⁺HLA-DR⁺ cells (p = 0.0186) and reduction in TNF-α secretion from BB-12- (p = 0.0490) or LPS-stimulated (p = 0.0387) PBMCs compared to baseline.

Conclusions

These findings not only demonstrate a potential anti-inflammatory effect of BB-12 in healthy adults, but also indicate that the delivery matrix influences the immunomodulatory properties of BB-12.

     

Stress-Induced Transcriptional Changes and DNA Damage Associated with Bis(2-ethylhexyl) Adipate Exposure in Zebrafish (<Emphasis Type="Italic">Danio rerio</Emphasis>) Larvae

The present study evaluates potential toxic effects of bis(2-ethylhexyl) adipate (DEHA) plasticizer to larval (72 h post fertilization) zebrafish (Danio rerio) by analyzing changes in expression levels of stress-related genes (p53, rad51 and xrcc5) and assessing possible DNA damage of DEHA in larvae. The lethal concentration for 50% mortality (LC₅₀) in larval zebrafish exposed for 96 h to 0–200 mg L^?1 DEHA was 89.9?±?8.03 mg L^?1. A concentration-dependent increase in DNA strand breaks was detected in cells from larvae exposed for 96 h to DEHA. There were some significant differences in induction of stress-related genes in larvae exposed to DEHA relative to control.     

Bioaccumulation of Dietary Endocrine Disrupting Chemicals (EDCs) by the Polychaete, <Emphasis Type="Italic">Perinereis nuntia</Emphasis>

To investigate the biomagnification factor (BMF) of EDCs by the polychaete, Perinereis nuntia, organisms were exposed to EDCs through their diet. BMF values ranged from 0.001 to 0.028 indicating that EDCs were not biomagnified. Elimination rates were (0.20–0.25 day^?1) and were higher than uptake rate (0.0003–0.003 day^?1) verifying that EDCs were not biomagnified by P. nuntia due to their fast elimination. The calculated half-life of each EDC in this study varies from 2.76 to 3.45 days. Overall, the findings from this study demonstrated that the studied EDCs are not biomagnified in P. nuntia but exposure does occur from the diet.     

Effects of 12-week supplementation of <Emphasis Type="Italic">Citrus bergamia</Emphasis> extracts-based formulation CitriCholess on cholesterol and body weight in older adults with dyslipidemia: a randomized,double-blind,placebo-controlled trial

Backgrounds

Recent experiments suggest that Citrus bergamia extracts could benefit people with dyslipidemia and obesity but this needs to be further validated.

Methods

A total of 98 people age-matched older adults (65 years) with elevated blood lipids were enrolled to receive 12-week supplementation of a Citrus bergamia extracts-based formulation (CitriCholess)(n?=?48) and placebo (n?=?50).

Results

No group differences were found in baseline bodyweight, body mass index (BMI), blood cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C) and glucose levels. CitriCholess supplementation resulted in lower levels than placebo in TG (1.83?±?0.92 vs. 1.95?±?1.34 mmol/L, P?=?0.612), TC (5.14?±?0.98 vs. 5.44?±?0.77 mmol/L, P?=?0.097), and LDL-C (3.13?±?0.74 vs. 3.43?±?0.62 mmol/L, P?=?0.032). Compared to placebo, CitriCholess also resulted in greater reductions in body weight (?0.604?±?0.939 vs. 0.06?±?0.74 kg, P?<?0.01), waist circumferences (?0.60?±?1.349 cm vs. -0.16?±?1.503 cm, P?<?0.01) and BMI (?0.207?±?0.357 vs. 0.025?±?0.274, P?<?0.01). Additionally, females had a significantly higher level of HDL-C than males. TC was significantly correlated with LDL-C, and to a less degree, with TG. TG was inversely correlated with HDL-C. Body weight and waist circumference were negatively correlated with HDL-C and positively correlated with glucose.

Conclusion

12-week supplementation of CitriCholess could benefit lipid metabolism and weight management in old adults with dyslipidemia.

     

Partial Gene Sequencing of CYP1A,Vitellogenin, and Metallothionein in Mosquitofish <Emphasis Type="Italic">Gambusia yucatana</Emphasis> and <Emphasis Type="Italic">Gambusia sexradiata</Emphasis>

Ground characteristics in the Yucatan Peninsula make recovery and treatment of wastewater very expensive. This situation has contributed to an increase of pollutants in the aquifer. Unfortunately, studies related to the effects of those pollutants in native organisms are scarce. The aim of this work was to obtain partial sequences of widely known genes used as biomarkers of pollutant effect in Gambusia yucatana and Gambusia sexradiata. The studied genes were: cytochrome P450 1A (CYP1A); vitellogenin (VTG); metallothionein (MT), and two housekeeping genes, 18S and β-actin. From reported sequences of Gambusia affinis, primers were designed and amplification was done in the local Gambusia species exposed for 48 h to gasoline (100 µL/L, stirred for 24 h pre-exposure). Preliminary results revealed partial sequences of all genes with an approximate average length of 200 bp. BLAST analysis of found sequences indicated a minimum of 97% identity with reported sequences for G. affinis or Gambusia holbrooki showing great similarity.