Summary

生存時間の測定で<em> Brachionus</em>ワムシ:母性条件の同期

Published: July 22, 2016
doi:

Summary

Rotifers are microscopic zooplankton used as models in ecotoxicological and aging studies. Here we provide a protocol for powerful and reproducible measurement of survival time in Brachionus rotifers. Synchronization of culture conditions over several generations is of particular importance because maternal condition affects life history of offspring.

Abstract

Rotifers are microscopic cosmopolitan zooplankton used as models in ecotoxicological and aging studies due to their several advantages such as short lifespan, ease of culture, and parthenogenesis that enables clonal culture. However, caution is required when measuring their survival time as it is affected by maternal age and maternal feeding conditions. Here we provide a protocol for powerful and reproducible measurement of the survival time in Brachionus rotifers following a careful synchronization of culture conditions over several generations. Empirically, poor synchronization results in early mortality and a gradual decrease in survival rate, thus resulting in weak statistical power. Indeed, under such conditions, calorie restriction (CR) failed to significantly extend the lifespan of B. plicatilis although CR-induced longevity has been demonstrated with well-synchronized rotifer samples in past and present studies. This protocol is probably useful for other invertebrate models, including the fruitfly Drosophila melanogaster and the nematode Caenorhabditis elegans, because maternal age effects have also been reported in these species.

Introduction

ワムシは門ワムシ1を構成する微細な国際的な動物プランクトン(<1ミリメートル)です。彼らは、約1,000体細胞から成るシンプルなボディープランだけでなく、特徴的な車輪状の毛様体装置が移動し、給餌のために使用されているコロナと呼ばれています。ほとんどのワムシはそれぞれ2、約1600と500種を含むクラスMonogonontaまたはヒルガタワムシ綱に属します。 bdelloidワムシが義務付け単為生殖3によって再生するMonogonontワムシは、一般的に、両方の性的および無性生殖相(循環的単為生殖を)持っています。実験において高い再現性を保証する、遺伝的に同一のワムシの個体を得ることができます。さらに、それらは、短い寿命、培養の容易さ、ゲノム及びトランスクリプトーム配列データ4-7の可用性、およびから離れユニークな系統発生位置などのモデル生物のようないくつかの他の利点を有しますrthropodsと線虫8。ワムシは、したがって、生態系における無脊椎動物のモデルを有望な毒物学、および研究9-12を老化されています。

環境ストレスや化学物質への曝露下での生存時間は、これらの研究分野13-19で頻繁に測定されたパラメータです。ワムシの生存時間を測定する場合、それは母親の環境条件に敏感であるためしかし、注意が必要です。すなわち、monogonontワムシBrachionus manjavacas高齢者の母親からの女性の子孫は、若い母親からのものよりも短い寿命を持っています。しかし、母体のカロリー制限(CR)は、部分的に高齢出産20の有害な影響を相殺します。 B.plicatilis、母体のCRは、子孫の長寿、飢餓の下で長い生存期間、および抗酸化酵素21,22の発現増強に伴う高い酸化ストレス耐性を提供します。母体の年齢効果またbdelloidワムシ23で観察されています。したがって、実験ワムシの条件は慎重に生存時間の測定の前に数世代にわたって同期する必要があります。

ここでは、数世代にわたって培養条件の同期以下のBrachionusのワムシでの生存時間を測定するためのプロトコルを提供します。間欠絶食(IF)、ワムシは、定期的に供給されるCRの変化は、原因寿命22,24にIFのよく知られた効果のために、同期の影響を明らかにするために適用しました。

Protocol

メディアの調製注意:使用して、塩分16.5 PPT(PSU)の半希釈Brujewicz人工海水を。他の人工海水にも頻繁に文化Brachionusのワムシ25,26に使用されています。 454のNaCl、26のMgCl 2、27mMのMgSO 4を、10のKCl、および10mMのCaCl 2(最終容量は5 Lになります)の蒸留水4.5 Lに追加します。また、脱イオン希釈水の代わりに蒸留水を使用してい?…

Representative Results

図1は不十分同期集団(2つの複製のうち)の代表的な生存曲線を示しています。この実験では、ワムシは、供給された日常の[ 自由摂取 (AL)グループ]または隔日(グループIF)のいずれかでした。生存期間中央値はそれぞれ、ALおよびIFグループで13と18日でした。よくIFは、ワムシの寿命を延長することが知られているが、この実験では、ALと…

Discussion

現在のプロトコルはBrachionusのワムシの生存時間を測定するための方法が記載されています。重要なステップは、数世代にわたるワムシ条件の同期です。実験ワムシはよく同期化されるとき、典型的なタイプIの生存曲線は、いくつかの以前の研究18,24,37,38で報告されたように、非常に小さな初期の死亡率が観察されます。彼らの生存時間の標準偏差が高いため、統計的パワーで?…

Disclosures

The authors have nothing to disclose.

Acknowledgements

私たちは、撮影中の彼らの助けのために、ジョージ・ジャービス、マーサボック、およびベティヒーコックス-リー、海洋生物学研究所に感謝しています。

Materials

Sodium chloride Wako 190-13921
Magnesium chloride Wako 136-03995
Magnesium sulfate Wako 131-00427
Potassium chloride Wako 168-22111
Calcium chloride Wako 035-00455
Sodium bicarbonate Wako 199-05985
Sodium bromide Wako 190-01515
Membrane filter (0.45 µm pore size) Millipore HAWP04700
Culture plate, 6-well, non-treated Thomas Scientific 6902D01 Flat bottom
Culture plate, 48-well, non-treated Thomas Scientific 6902D07 Flat bottom
Tetraselmis, Living Carolina Biological Supply Company 152610
PRISM 6 GraphPad Software Version 6.0d

References

  1. Wallace, R. L., Snell, T. W., Ricci, C., Nogrady, T. . Rotifera Vol.1: Biology, ecology and systematics. , (2006).
  2. Segers, H. . Annotated checklist of the rotifers (Phylum Rotifera), with notes on nomenclature, taxonomy and distribution. , (2007).
  3. Mark Welch, D. B., Meselson, M. Evidence for the evolution of bdelloid rotifers without sexual reproduction or genetic exchange. Science. 288 (5469), 1211-1215 (2000).
  4. Suga, K., Mark Welch, D., Tanaka, Y., Sakakura, Y., Hagiwara, A. Analysis of expressed sequence tags of the cyclically parthenogenetic rotifer Brachionus plicatilis. PLoS ONE. 2, e671 (2007).
  5. Denekamp, N. Y., et al. Discovering genes associated with dormancy in the monogonont rotifer Brachionus plicatilis. BMC Genomics. 10, 108 (2009).
  6. Lee, J. -. S., et al. Sequence analysis of genomic DNA (680 Mb) by GS-FLX-Titanium sequencer in the monogonont rotifer, Brachionus ibericus. Hydrobiologia. 662 (1), 65-75 (2010).
  7. Flot, J. -. F., et al. Genomic evidence for ameiotic evolution in the bdelloid rotifer Adineta vaga. Nature. 500 (7463), 453-457 (2013).
  8. Dunn, C. W., et al. Broad phylogenomic sampling improves resolution of the animal tree of life. Nature. 452 (7188), 745-749 (2008).
  9. Yoshinaga, T., Kaneko, G., Kinoshita, S., Tsukamoto, K., Watabe, S. The molecular mechanisms of life history alterations in a rotifer: a novel approach in population dynamics. Comp. Biochem. Physiol. B Biochem. Mol. Biol. 136 (4), 715-722 (2003).
  10. Dahms, H. -. U., Hagiwara, A., Lee, J. -. S. Ecotoxicology, ecophysiology, and mechanistic studies with rotifers. Aquat. Toxicol. 101 (1), 1-12 (2011).
  11. Snell, T. W. Rotifers as models for the biology of aging. Int. Rev. Hydrobiol. 99 (1-2), 84-95 (2014).
  12. Snell, T. W., Johnston, R. K., Gribble, K. E., Mark Welch, D. B. Rotifers as experimental tools for investigating aging. Invertebr. Reprod. Dev. 59, 5-10 (2015).
  13. Kaneko, G., et al. Molecular characterization of Mn-superoxide dismutase and gene expression studies in dietary restricted Brachionus plicatilis rotifers. Hydrobiologia. 546, 117-123 (2005).
  14. Yoshinaga, T., et al. Insulin-like growth factor signaling pathway involved in regulating longevity of rotifers. Hydrobiologia. 546, 347-352 (2005).
  15. Ozaki, Y., Kaneko, G., Yanagawa, Y., Watabe, S. Calorie restriction in the rotifer Brachionus plicatilis enhances hypoxia tolerance in association with the increased mRNA levels of glycolytic enzymes. Hydrobiologia. 649 (1), 267-277 (2010).
  16. Kailasam, M., et al. Effects of calorie restriction on the expression of manganese superoxide dismutase and catalase under oxidative stress conditions in the rotifer Brachionus plicatilis. Fish. Sci. 77 (3), 403-409 (2011).
  17. Garcìa-Garcìa, G., Sarma, S., Núñez-Orti, A. R., Nandini, S. Effects of the mixture of two endocrine disruptors (ethinylestradiol and levonorgestrel) on selected ecological endpoints of Anuraeopsis fissa and Brachionus calyciflorus (Rotifera). Int. Rev. Hydrobiol. 99 (1-2), 166-172 (2014).
  18. Yang, J., Mu, Y., Dong, S., Jiang, Q., Yang, J. Changes in the expression of four heat shock proteins during the aging process in Brachionus calyciflorus (rotifera). Cell Stress Chaperones. 19 (1), 33-52 (2014).
  19. Han, J., et al. Sublethal gamma irradiation affects reproductive impairment and elevates antioxidant enzyme and DNA repair activities in the monogonont rotifer Brachionus koreanus. Aquat. Toxicol. 155, 101-109 (2014).
  20. Gribble, K. E., Jarvis, G., Bock, M., Mark Welch, D. B. Maternal caloric restriction partially rescues the deleterious effects of advanced maternal age on offspring. Aging Cell. 13 (4), 623-630 (2014).
  21. Yoshinaga, T., Hagiwara, A., Tsukamoto, K. Effect of periodical starvation on the survival of offspring in the rotifer Brachionus plicatilis. Fish. Sci. 67 (2), 373-374 (2001).
  22. Kaneko, G., et al. Calorie restriction-induced maternal longevity is transmitted to their daughters in a rotifer. Funct. Ecol. 25 (1), 209-216 (2011).
  23. Lansing, A. I. A transmissible, cumulative, and reversible factor in aging. J. Gerontol. 2 (3), 228-239 (1947).
  24. Yoshinaga, T., Hagiwara, A., Tsukamoto, K. Effect of periodical starvation on the life history of Brachionus plicatilis O. F. Müller (Rotifera): a possible strategy for population stability. J. Exp. Mar. Biol. Ecol. 253 (2), 253-260 (2000).
  25. Gribble, K. E., Kaido, O., Jarvis, G., Mark Welch, D. B. Patterns of intraspecific variability in the response to caloric restriction. Exp. Gerontol. 51, 28-37 (2014).
  26. Snell, T. W., Johnston, R. K. Glycerol extends lifespan of Brachionus manjavacas (Rotifera) and protects against stressors. Exp. Gerontol. 57, 47-56 (2014).
  27. Kim, H. -. J., Hagiwara, A. Effect of female aging on the morphology and hatchability of resting eggs in the rotifer Brachionus plicatilis Müller. Hydrobiologia. 662 (1), 107-111 (2011).
  28. Kim, H. -. J., et al. Light-dependent transcriptional events during resting egg hatching of the rotifer Brachionus manjavacas. Mar. Genomics. 20, 25-31 (2015).
  29. Gribble, K. E., Welch, D. B. M. Life-span extension by caloric restriction is determined by type and level of food reduction and by reproductive mode in Brachionus manjavacas (Rotifera). J. Gerontol. A Biol. Sci. Med. Sci. 68 (4), 349-358 (2013).
  30. Kaneko, G., Kinoshita, S., Yoshinaga, T., Tsukamoto, K., Watabe, S. Changes in expression patterns of stress protein genes during population growth of the rotifer Brachionus plicatilis. Fish. Sci. 68 (6), 1317-1323 (2002).
  31. Kim, H. J., Sawada, C., Hagiwara, A. Behavior and reproduction of the rotifer Brachionus plicatilis species complex under different light wavelengths and intensities. Int. Rev. Hydrobiol. 99 (1-2), 151-156 (2014).
  32. Yoshinaga, T., Hagiwara, A., Tsukamoto, K. Effect of conditioned media on the asexual reproduction of the monogonont rotifer Brachionus plicatilis O. F. Müller. Hydrobiologia. 412, 103-110 (1999).
  33. Ohmori, F., Kaneko, G., Saito, T., Watabe, S. A novel growth-promoting protein in the conditioned media from the rotifer Brachionus plicatilis at an early exponential growth phase. Hydrobiologia. 667 (1), 101-117 (2011).
  34. Collet, D. . Modelling Survival Data in Medical Research. , 151-193 (1993).
  35. Bouliotis, G., Billingham, L. Crossing survival curves: alternatives to the log-rank test. Trials. 12, A137 (2011).
  36. Yang, J., et al. Changes in expression of manganese superoxide dismutase, copper and zinc superoxide dismutase and catalase in Brachionus calyciflorus during the aging process. PloS ONE. 8 (2), e57186 (2013).
  37. Snell, T. W., Johnston, R. K., Rabeneck, B., Zipperer, C., Teat, S. Joint inhibition of TOR and JNK pathways interacts to extend the lifespan of Brachionus manjavacas (Rotifera). Exp. Gerontol. 52, 55-69 (2014).
  38. Klass, M. R. Aging in nematode Caenorhabditis-elegans – major biological and environmental-factors influencing life-span. Mech. Ageing Dev. 6 (6), 413-429 (1977).
  39. Priest, N. K., Mackowiak, B., Promislow, D. E. L. The role of parental age effects on the evolution of aging. Evolution. 56 (5), 927-935 (2002).
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Kaneko, G., Yoshinaga, T., Gribble, K. E., Welch, D. M., Ushio, H. Measurement of Survival Time in Brachionus Rotifers: Synchronization of Maternal Conditions. J. Vis. Exp. (113), e54126, doi:10.3791/54126 (2016).

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