Effects of some space flight factors on survivorship in crustacean resting stages

V.R. Alekseev*, M.A. Levinskih**, N.D. Novikova**, V.N.Sychev**, T. Okuda***, *Zoological Institute of RAS, St. Petersburg, Russia ** Institute for biomedical problems RAS, Moscow, Russia *** National Institute of Agrobiological Science, Tsukuba , Japan

In accordance with the Russian space research program, the study on cryptobiosis is important for: • • • Planetary and space craft quarantine Ecosystem transportation outside The Earth Biosphere Extraterrestrial life searching (Alekseev, Sychev, Novikova 2007)

During space flight organisms are affected by a set of factors different from Earth conditions 1.

2.

3.

4.

5.

6.

Microgravity Space (corpuscular) radiation Transformed magnetic field Over gravity (during start) Industrial factors (noise, vibration, electro-magnetic field) Varies combinations of 1-5 with possible synergic effects

OBJECTIVES of this study:

• • to find out if Factors of Space Flight (FSF) play a negative role in vital abilities of cryptobiotic stages if YES, what kind of effects the FSF on dormant stages can we get than and how to overcome the effects by before-flight measures

Two types of space experiments were conducted

1.

“AQUARIUM” experiment: Cryptobiotic stages were transported to ISS (Russian segment) and exposed 1-8 months INSIDE station

Resting stages of two species were selected for this experiment in space A phyllopod crustacean

Streptocephalus torvicornis

A cladoceran

Daphnia magna

Материал:

• • D. magna и S. torvicornis дельте Волги собирались в дафниевых прудах осетрового рыбзавода в В этих прудах на протяжении 30 лет формировалась микроэкосистема из организмов способных к длительному биологическому покою.

2. “Biorisk” experiment: cryptobiotic stages were placed for 13-18 months OUTSIDE ISSS

1. Hatching of resting egg exposed inside ISS • • • Hatching started on the third day after moving from 10 o to 25 o C The reactivation rate : in ISS 39.6 % (30.6) In control 51,8 % (39.9) (t-test; p=0.035)

Average body mass in newborn Daphnia after ISS treatment within one month

Сухой вес, мг 0.007

0.006

0.005

0.004

0.003

0.002

0.001

0 10/27 10/28 10/29 10/30 10/31 11/1 11/2 Даты 11/3 11/4 11/5 11/6 11/7

Серии

Size and reactivation in Daphnia

Hatching of D. magna in control and after 1 month ISS treatment

First 25 20 15 10 Medium Post 5 0 1 3 4 5 6

Сухой вес, мг 0.007

7

0.006

0.005

8 9 10 11 12 13 14 15 16

0.004

0.003

0.002

0.001

0 10/27 10/28 10/29 10/30 10/31 11/1 11/2 Даты 11/3 11/4 11/5 11/6 11/7

Серии Control Flight

Differences in time of reactivation among clones confirmed with PCR • • • F - first group M – middle group P – posterior group

Discriminative analyze based on 24 signs revealed that time of reactivation in 3 clones were genetically specified 7 6 5 4 3 2 1 0 -1 -2 -3 Root 1 vs. Root 2 • • • F - first group M – middle group P – posterior group -4 -5 -8 -6 -4 -2 0 2 4 6 F M P Root 1

Effect of neutron radiation on D. magna hatching(%) from resting eggs 10 9 8 7 6 5 4 3 2 1 0 24.04.2006

01.05.2006

1. 2 week NR Hatching =16.3+17.29% 2. 4 week NR Hatching = 23.5+18.16% 3. Control Hatching = 35.5 +20.75%

p

1-3=0,1

08.05.2006

Dates

p2

-3=0.22

15.05.2006

NR Control

FSF also affected some life cycle parameters in

D. magna

.

• The first clutch size : in ISS-treated (11+3.6 egg i -1 ) in control group (14.3+2.8 egg i -1 ) ( t-test; p =0.0477).

•

Maturation time:

in ISS (9.95+0.284 day) in control (10.31+0.372 day) (Mann-Whitney test z adjust =2.09, p =0.033).

Males in

D. magna

in offspring.

• • In ISS offspring 54.9+25.94% males No a single male in offspring from control group!

•

S. torvicornis

resting eggs were used to trace increasing of negative changes with time Resting eggs of this species were collected in the same ponds in density several times more than ephippia Daphnia

Reactivation in S. torvicornis after ISS and in control

30 25 20 15 10 5 0 1 2 3 4 5 6 7 8

Days after start

9 10 11 12 13 14 ISS Control

Effect of resting egss exposing at ISS on

S. torvicornis

hatching Control group 1 month exposing, hatching/150 cysts 42+8 8 month exposing, hatching/150 cysts 53+13 Experimental group 21+6 11.2+1,5

• • • • • • • 2. Nine species were selected to study effect of open space conditions Daphnia magna (winter dormancy) Daphnia pulicaria (summer dormancy) Streptocephalus torvicornis Artemia salina Eucycpris ornata Polypedium vanderplankii Nothobranchius guenteri (eggs of African fish)

Sleeping under the Sun

Results of “Biorisk” treatments

• • • • • • • Daphnia magna Daphnia pulicaria Streptocephalus torvicornis Eucycpris ornata Nothobranchius guenteri Polypedium vanderplankii Artemia salina • • • • • • • Survived Died Survived Survived Died Survived Survived

Trehalose content in resting stages

Species Daphnia, large ephippia (our data) Daphnia large ephippia (our data) Ostracoda ( our data) Streptocephalus (large) our data Streptocephalus (small) our data Artemia (after Clegg, 1965) P. vanderplanki (after Kikawada et al., 2007) HIR

Code

DSE DLE OST SLC SSC ART Trehalose , % 24.951

19.8677

17.3826

25.07

8.5

15 20

100

Trehalose content and resting stage reactivation

10 Trehalose, % Reactivation, % 1 DSE DLE OST SLC

SPECIES

SSC ART HIR

Conclusions:

• • • Cryptobiotic stages of aquatic invertebrates are effected by FSF inside space station but also are able to overcome them outside station Space radiation seems like responsible for main negative effect inside station exposing Resistance to FSF in most species studied was related with trehalose content in their bodies that can help for before-flight selection/preparation the most resistant to FSF specimens

Acknowledgments:

• • • This study was supported by RFBR-Japan bilateral grants VA got a fellowship from Max-Planck-Society Drs. N. Abramson. T. Kikawada, O. Gusev and Prof. Vladimir Tzetlin are very much appreciated for significant help in experiments and productive discussion on their results THANK YOU FOR ATTENTION!