Daria Bedulina

Laboratory of biosystem adaptation Irkutsk State University

Adviser: Dr M. Timofeev

Modification of MXR-activity in freshwater amphipods Eulimnogammarus cyaneus

and E. verrucosus by organic and inorganic contaminants.

Organism

STRESSADAPTATION

The organisms stress adaptation levels:

1. Behavioral2. Physiological3. Biochemical and molecular

Multixenobiotic resistance system (MXR)

P-glycoprotein(P-gp)

Multixenobiotic resistance system (MXR)

Method of MXR-activity definition:

Rhodamine B efflux method

LAKE BAIKAL

Lake Baikal

Amphipods (Crustacea, Amphipoda) More than 250 species and subspecies

Fauna >> 2500 species (60-80% endemics)

Contaminants, used in research

Organic contaminant Natural organic matter (NOM)

Inorganic contaminant CdCl2

Humic substances

22

The objects of research:

Eulimnogammarus verrucosus (Gerstf.)

E.cyaneus (Dyb.)

P-gp

Rhodamine B-efflux method

Accumulation

P-gp

Rhodamine B-efflux method

Efflux

MXR-activity in amphipodsMXR-activity in amphipods

without contaminants (control)

(Rhodamine B efflux ))

Eulimnogammarus cyaneus Eulimnogammarus verrucosus

Results

MXR-activity in amphipods, MXR-activity in amphipods,

NOM solutions (60 mg/ml)

(Rhodamine B efflux ))

Eulimnogammarus cyaneus Eulimnogammarus verrucosus

control

NOM

Results

Eulimnogammarus cyaneus Eulimnogammarus verrucosus

control

CdCl2

Results

Discussion

1. Baikalian amphipods use a MXR system for xenobiotics efflux.

2. Activity of this system is inhibited by some organic and inorganic contaminants.

Conclusion

The multixenobiotic resistance mechanism in baikalian organisms is sensitive to organic and inorganic contaminants, such as heavy metal and NOM.

This research was partially supported by grants of Russian Foundation for Basic Research

No. 05-04-97239-Baikal, 05-04-97263-Baikal

and 06-04-48099

The presented results was published

Timofeyev M.,  Shatilina Z.M., Bedulina D.S., Menzel, R., Steinberg C.E.W. Natural organic matter (NOM) has the potential to modify the multixenobiotic resistance (MXR) activity in freshwater amphipods Eulimnogammarus cyaneus (Dyb) and Eulimnogammarus verrucosus (Gerst.)// Comparative biochemistry and physiology, Part B 146 (2007) 496–503 

Thank you!